Beta Advantage ^® ETFs

Columbia Diversified
Fixed Income Allocation ETF

    

Ticker Symbol

DIAL

This prospectus provides important information about Columbia Diversified Fixed Income Allocation ETF (the Fund), a passively managed exchange-traded fund (the ETF) and series of Columbia ETF Trust I (the Trust), that you should know before investing. Please read it carefully and keep it for future reference.

These securities have not been approved or disapproved by the Securities and Exchange Commission (SEC) nor has the SEC passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Shares of the Fund are listed and traded on NYSE Arca, Inc. (the Exchange).

No person has been authorized to give any information or to make any representations other than those contained in this prospectus and the Fund's Statement of Additional Information (SAI) dated March 1, 2019 (which is incorporated by reference into this prospectus and is legally a part of this prospectus) and, if given or made, such information or representations may not be relied upon as having been authorized by us.

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund (continued)

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund (continued)

companies, utilities, and financial institutions) that meet the following criteria: have a remaining maturity of between and including 5 to 15 years, a credit rating between and including BAA1 and BAA3 using the Bloomberg Barclays index rating methodology, and an issuance date not greater than 1,000 days. The two largest issues from each issuer are selected based on amount outstanding. At January 31, 2019, this sector index model held 504 securities.

Beta Advantage ^® Strategy to Investing in the U.S. Corporate High Yield Debt Sector . As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the Bloomberg Barclays US Corporate High Yield Total Return Index (which is comprised of publicly issued U.S. dollar denominated, non-investment grade, fixed-rate, taxable corporate bonds) that meet the following criteria: have a (non-investment grade) credit rating above B3 using the Bloomberg index rating methodology, an outstanding face amount greater than $800 million, remaining maturity of less than 14 years, and issued within the past 5 years. Pay-in-kind (PIK) and partial PIK instruments are excluded from this sector index model. The two largest issues from each issuer are selected based on amount outstanding, subject to a 2% issuer cap based on market value. At January 31, 2019, this sector index model held 177 securities.

Beta Advantage ^® Strategy to Investing in the Emerging Markets Sovereign and Quasi-Sovereign Debt Sector . As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the Bloomberg Barclays Emerging Markets USD Aggregate Total Return Index (which is comprised of fixed-rate sovereign and quasi-sovereign debt of emerging market countries rated investment grade and non-investment grade) that meet the following criteria, with corporate issuers being excluded: have a credit rating between and including BAA1 and BA3 using the Bloomberg Barclays index rating methodology, remaining maturity of between and including 5 to 15 years, and a minimum amount outstanding of at least $2 billion. The two largest issues from each issuer are selected based on amount outstanding, subject to a maximum 10% country weighting (based on market value). At January 31, 2019, this sector index model held 62 securities.

The Fund may invest, as part of its 80% investment policy or otherwise when the Investment Manager believes it will help the Fund track the Index, in privately placed and other securities or instruments that are purchased and sold pursuant to Rule 144A or other exemptions under the Securities Act of 1933, as amended (the 1933 Act), subject to liquidity determinations and certain regulatory restrictions.

The Index (as well as the six sector index models) are reconstituted and rebalanced monthly on the last business day of each month.

As noted above, the six sector index models will generate all of the component securities of the Index. Columbia Management expects to utilize a “representative sampling” strategy whereby the Fund invests in only some of the component securities of the Index that, collectively, are believed by the Investment Manager to generally reflect the same risk and return characteristics of the Index. As such, the Fund may not track the Index with the same degree of accuracy as would an investment vehicle replicating (or investing in) the entire Index. Through its representative sampling investment technique, the Fund expects to typically hold 200 to 250 holdings, which is a subset of the total number of holdings in the Index, which, as of January 31, 2019, had 180 holdings. There may be instances in which the Fund may overweight (or underweight) an Index holding, purchase (or sell) instruments not in the Index as a substitute for one or more securities in the Index or utilize various combinations of other available investment techniques in seeking to replicate the performance of the Index. Under certain circumstances or conditions or due to other factors, including, for example, the size of the Fund (in terms of assets under management), the Fund may increase its number of holdings beyond the typical range of holdings stated above.

The Fund may sell securities or other holdings that are represented in the Index or purchase securities or make other investments that are not yet represented in the Index in anticipation of their removal from or addition to the Index by the Index Provider.

The Investment Manager does not invest the Fund’s assets based on its view of the investment merits of a particular security or company, neither does it conduct fundamental investment research or analysis, nor seek to forecast or otherwise consider market movements, conditions or trends in managing the Fund’s assets. The Fund pursues its investment objective of correlating performance with the Index regardless of market conditions and does not take defensive positions.

Prospectus 2019

5

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund (continued)

To the extent the Index is concentrated in a particular sector or industry, the Fund will necessarily be concentrated in that sector or industry.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Authorized Participant Concentration Risk. Only an Authorized Participant (as defined below) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units, Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund share level and at the Fund holdings level.

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.

Concentration Risk. The Fund will concentrate its investments in companies conducting business in a related group of industries within a sector(s) to approximately the same extent as the Index. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly a fund diversifies its investments, the more it spreads risk and potentially reduces the risks of loss and volatility.

Correlation/Tracking Error Risk. The Fund’s value will generally decline when the performance of the Index declines. A number of factors may affect the Fund’s ability to achieve a high degree of correlation with the Index, and there is no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation may prevent the Fund from achieving its investment objective. The Fund also bears management and other expenses and transaction costs in trading securities or other instruments, which the Index does not bear. Accordingly, the Fund’s performance will likely fail to match the performance of the Index, after taking expenses into account. It is not possible to invest directly in an index.

Counterparty Risk. Counterparty risk is the risk that a counterparty to a transaction in a financial instrument held by the Fund or by a special purpose or structured vehicle invested in by the Fund may become insolvent or otherwise fail to perform its obligations. As a result, the Fund may obtain no or limited recovery of its investment, and any recovery may be significantly delayed.

Credit Risk. Credit risk is the risk that the value of debt instruments may decline if the borrower or the issuer thereof defaults or otherwise becomes unable or unwilling, or is perceived to be unable or unwilling, to honor its financial obligations, such as making payments to the Fund when due. Rating agencies assign credit ratings to certain debt instruments to indicate their credit risk. Unless otherwise provided in the Fund’s Principal Investment Strategies, investment grade debt instruments are those rated at or above BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. Conversely, below investment grade (commonly called “high-yield” or “junk”) debt instruments are those rated below BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. A rating downgrade by such agencies can negatively impact the value of such instruments. Lower quality or unrated instruments held by the Fund may present increased credit risk as compared to higher-rated instruments. Non-investment grade debt instruments may

6	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund (continued)

be subject to greater price fluctuations and are more likely to experience a default than investment grade debt instruments and therefore may expose the Fund to increased credit risk. If the Fund purchases unrated instruments, or if the ratings of instruments held by the Fund are lowered after purchase, the Fund will depend on analysis of credit risk more heavily than usual. If the issuer of a loan declares bankruptcy or is declared bankrupt, there may be a delay before the Fund can act on the collateral securing the loan, which may adversely affect the Fund. Further, there is a risk that a court could take action with respect to a loan that is adverse to the holders of the loan. Such actions may include invalidating the loan, the lien on the collateral, the priority status of the loan, or ordering the refund of interest previously paid by the borrower. Any such actions by a court could adversely affect the Fund’s performance. A default or expected default of a loan could also make it difficult for the Fund to sell the loan at a price approximating the value previously placed on it. In order to enforce its rights in the event of a default, bankruptcy or similar situation, the Fund may be required to retain legal or similar counsel. This may increase the Fund’s operating expenses and adversely affect its NAV. Loans that have a lower priority for repayment in an issuer’s capital structure may involve a higher degree of overall risk than more senior loans of the same borrower.

Depositary Receipts Risk. Depositary receipts are receipts issued by a bank or trust company reflecting ownership of underlying securities issued by foreign companies. Some foreign securities are traded in the form of American Depositary Receipts and/or Global Depositary Receipts. Depositary receipts involve risks similar to the risks associated with investments in foreign securities, including those associated with investing in the particular country of an issuer, which may be related to the particular political, regulatory, economic, social and other conditions or events, including, for example, military confrontations, war and terrorism, occurring in the country and fluctuations in such country’s currency, as well as market risk tied to the underlying foreign company. In addition, holders of depositary receipts may have limited voting rights, may not have the same rights afforded to stockholders of a typical domestic company in the event of a corporate action, such as an acquisition, merger or rights offering, and may experience difficulty in receiving company stockholder communications. There is no guarantee that a financial institution will continue to sponsor a depositary receipt, or that a depositary receipt will continue to trade on an exchange, either of which could adversely affect the liquidity, availability and pricing of the depositary receipt. Changes in foreign currency exchange rates will affect the value of depositary receipts and, therefore, may affect the value of your investment in the Fund. To the extent that the exchange price of a depositary receipt differs from the local price of the underlying security used by the Index, the Fund may be prevented from fully achieving its investment objective of tracking the performance of the Index.

Early Close/Late Close/Trading Halt Risk.  An exchange or market may close early, close late or issue trading halts on specific securities, or the ability to buy or sell certain securities may be restricted, which may result in the Fund being unable to buy or sell these securities. In these circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments, may incur substantial trading losses and/or may be prevented from sufficiently tracking the performance of the Index.

Emerging Market Securities Risk. Securities issued by foreign governments or companies in emerging market countries are more likely to have greater exposure to the risks of investing in foreign securities that are described in Foreign Securities Risk. In addition, emerging market countries are more likely to experience instability resulting, for example, from rapid changes or developments in social, political, economic or other conditions. Their economies are usually less mature and their securities markets are typically less developed with more limited trading activity (i.e., lower trading volumes and less liquidity) than more developed countries. Emerging market securities tend to be more volatile than securities in more developed markets. Many emerging market countries are heavily dependent on international trade and have fewer trading partners, which makes them more sensitive to world commodity prices and economic downturns in other countries, and some have a higher risk of currency devaluations.

Foreign Currency Risk. The performance of the Fund may be materially affected positively or negatively by foreign currency strength or weakness relative to the U.S. dollar, particularly if the Fund invests a significant percentage of its assets in foreign securities or other assets denominated in currencies other than the U.S. dollar.

Foreign Securities Risk. Investments in or exposure to foreign securities involve certain risks not associated with investments in or exposure to securities of U.S. companies. Foreign securities subject the Fund to the risks associated with investing in the particular country of an issuer, including political, regulatory, economic, social, diplomatic and other conditions or events (including, for example, military confrontations, war and terrorism),

Prospectus 2019

7

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund (continued)

occurring in the country or region, as well as risks associated with less developed custody and settlement practices. Foreign securities may be more volatile and less liquid than securities of U.S. companies, and are subject to the risks associated with potential imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the disposition of foreign securities, which could reduce the Fund’s return on such securities. The performance of the Fund may also be negatively affected by fluctuations in a foreign currency's strength or weakness relative to the U.S. dollar, particularly to the extent the Fund invests a significant percentage of its assets in foreign securities or other assets denominated in currencies other than the U.S. dollar. Additionally, the Fund’s foreign investments may trade in markets that may not be open on the same day or at the same time as the Fund, or foreign markets may close after the Fund has calculated its NAV for a given business day, which may cause a difference in the market price of such foreign securities and the value attributed to such securities by the Fund.

Forward Commitments on Mortgage-Backed Securities (including Dollar Rolls) Risk. When purchasing mortgage-backed securities in the “to be announced” (TBA) market (MBS TBAs), the seller agrees to deliver mortgage-backed securities for an agreed upon price on an agreed upon date, but may make no guarantee as to the specific securities to be delivered. In lieu of taking delivery of mortgage-backed securities, the Fund could enter into dollar rolls, which are transactions in which the Fund sells securities to a counterparty and simultaneously agrees to purchase those or similar securities in the future at a predetermined price. Dollar rolls involve the risk that the market value of the securities the Fund is obligated to repurchase may decline below the repurchase price, or that the counterparty may default on its obligations. These transactions may also increase the Fund’s portfolio turnover rate. If the Fund reinvests the proceeds of the security sold, the Fund will also be subject to the risk that the investments purchased with such proceeds will decline in value (a form of leverage risk). MBS TBAs and dollar rolls are subject to the risk that the counterparty to the transaction may not perform or be unable to perform in accordance with the terms of the instrument.

Fund Shares Liquidity Risk. Although the Fund’s shares are listed on the Exchange, there can be no assurance that an active, liquid or otherwise orderly trading market for shares will be established or maintained by market makers or Authorized Participants, particularly in times of stressed market conditions. In this regard, there is no obligation for market makers to make a market in the Fund’s shares or for Authorized Participants to submit purchase or redemption orders for creation units. Accordingly, if such parties determine not to perform their respective roles, this could, in turn, lead to variances between the market price of the Fund’s shares and the underlying value of those shares. Trading in Fund shares on the Exchange also may be disrupted or even halted due to market conditions or for reasons that, in the view of the Exchange, make trading in Fund shares inadvisable. In addition, trading in Fund shares on the Exchange may be subject to trading halts caused by extraordinary market volatility pursuant to the Exchange “circuit breaker” rules. There also can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund’s shares will continue to be met or will remain unchanged.

High-Yield Investments Risk. Securities and other debt instruments held by the Fund that are rated below investment grade (commonly called “high-yield” or “junk” bonds) and unrated debt instruments of comparable quality expose the Fund to a greater risk of loss of principal and income than a fund that invests solely or primarily in investment grade debt instruments. In addition, these investments have greater price fluctuations, are less liquid and are more likely to experience a default than higher-rated debt instruments. High-yield debt instruments are considered to be predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal.

Index Methodology Risk. The Fund seeks performance that corresponds to the performance of the Index. There is no guarantee or assurance that the Index will achieve high, or even positive, returns. The Index may underperform more traditional indices. The Fund could lose value while other indices or measures of market performance increase in value or performance. In addition, the Fund may be subject to the risk that the index provider may not follow its stated methodology for construction of the Index and/or achieve the index provider’s intended performance objective. Errors may result in a negative performance impact to the Fund and its shareholders.

Interest Rate Risk. Interest rate risk is the risk of losses attributable to changes in interest rates. In general, if prevailing interest rates rise, the values of debt instruments tend to fall, and if interest rates fall, the values of debt instruments tend to rise. Changes in the value of a debt instrument usually will not affect the amount of income the

8	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund (continued)

Fund receives from it but will generally affect the value of your investment in the Fund. Changes in interest rates may also affect the liquidity of the Fund’s investments in debt instruments. In general, the longer the maturity or duration of a debt instrument, the greater its sensitivity to changes in interest rates. Interest rate declines also may increase prepayments of debt obligations, which, in turn, would increase prepayment risk. Similarly, a period of rising interest rates may negatively impact the Fund’s performance. Actions by governments and central banking authorities can result in increases in interest rates. Such actions may negatively affect the value of debt instruments held by the Fund, resulting in a negative impact on the Fund's performance and NAV. Debt instruments with floating coupon rates are typically less sensitive to interest rate changes, but these debt instruments may decline in value if their coupon rates do not rise as much as, or keep pace with, yields on such types of debt instruments. Because rates on certain floating rate loans and other debt instruments reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause fluctuations in the Fund’s NAV. Any interest rate increases could cause the value of the Fund’s investments in debt instruments to decrease. Rising interest rates may prompt redemptions from the Fund, which may force the Fund to sell investments at a time when it is not advantageous to do so, which could result in losses.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors.

Limitations of Intraday Indicative Value (IIV) Risk. The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the business day, (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close, which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. For example, if the Fund fair values portfolio securities, the Fund’s NAV may deviate from the approximate per share value of the Fund’s published basket of portfolio securities (i.e., the IIV), which could result in the market prices for Fund shares deviating from NAV. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions of creation units, which may negatively impact Fund performance and NAV,

Prospectus 2019

9

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund (continued)

including, for example, if the Fund is forced to sell investments in a down market. In certain circumstances, the Fund might not be able to dispose of certain holdings quickly or at fair prices, preventing the Fund from tracking the Index. Foreign securities can present enhanced liquidity risks, including as a result of less developed custody, settlement or other practices of foreign markets. In addition, in stressed market conditions, the market for Fund shares may become less liquid. Deterioration in the liquidity of Fund shares may adversely impact the liquidity of the Fund's underlying portfolio securities. These adverse impacts on the liquidity of Fund shares and on the liquidity of the Fund's underlying portfolio securities could in turn lead to differences between the market price of Fund shares and the underlying value of those shares.

Market Price Relative to NAV Risk. Shares of the Fund may trade at prices that vary from Fund NAV. Shares of the Fund are listed for trading on the Exchange and are bought and sold in the secondary market at market prices that may differ, in some cases significantly, from their NAV. The NAV of the Fund will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of shares, however, will generally fluctuate in response to changes in NAV, as well as the relative supply of, and demand for, Fund shares on the Exchange. The Investment Manager cannot predict whether Fund shares will trade below, at or above their NAV. Price differences may result because of, among other factors, supply and demand forces in the secondary trading market for Fund shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings. In this connection, if a shareholder purchases Fund shares at a time when the market price is at a premium to the NAV or sells shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses. Different investment strategies or techniques, including those intended to be defensive in nature, including, as examples, stop loss orders to sell an ETF’s shares in the secondary market during negative market events or conditions, such as a “flash crash” or other market disruptions may not work as intended and may produce significant losses to investors. Investors should consult their financial intermediary prior to using any such investment strategies or techniques, or before investing in the Fund.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. An investment in the Fund could lose money over short or long periods.

Mortgage-Backed Securities Risk. The value of any mortgage-backed securities held by the Fund may be affected by, among other things, changes or perceived changes in: interest rates; factors concerning the interests in and structure of the issuer or the originator of the mortgages; the creditworthiness of the entities that provide any supporting letters of credit, surety bonds or other credit enhancements; or the market's assessment of the quality of underlying assets. Payment of principal and interest on some mortgage-backed securities (but not the market value of the securities themselves) may be guaranteed by the full faith and credit of a particular U.S. Government agency, authority, enterprise or instrumentality, and some, but not all, are also insured or guaranteed by the U.S. Government. Mortgage-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) may entail greater risk than obligations guaranteed by the U.S. Government. Mortgage--backed securities are subject to liquidity risk and prepayment risk. A decline or flattening of housing values may cause delinquencies in the mortgages (especially sub-prime or non-prime mortgages) underlying mortgage-backed securities and thereby adversely affect the ability of the mortgage-backed securities issuer to make principal and/or interest payments to mortgage-backed securities holders, including the Fund. Rising or high interest rates tend to extend the duration of mortgage--backed securities, making their prices more volatile and more sensitive to changes in interest rates.

Passive Investment Risk. The Fund is not “actively” managed and may be affected by a general decline in market segments related to its underlying index. The Fund invests in securities or instruments included in, or believed by the Investment Manager to be representative of, its underlying index, regardless of their investment merits. The Fund does not seek temporary defensive positions when markets decline or appear overvalued. The decision of whether to remove a security from an index is made by an independent index provider who is not affiliated with the Fund or the Investment Manager.

Portfolio Turnover Risk. The Fund may pay transaction costs, such as commissions and/or spreads, when it buys and sells securities or other holdings (or “turns over” its portfolio). High levels of transactions increase brokerage and other transaction costs and may result in increased taxable capital gains.

10	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund (continued)

Prepayment and Extension Risk. Prepayment and extension risk is the risk that a loan, bond or other security or investment might, in the case of prepayment risk, be called or otherwise converted, prepaid or redeemed before maturity and, in the case of extension risk, that the investment might not be called as expected. In the case of prepayment risk, if the investment is converted, prepaid or redeemed before maturity, the portfolio managers may not be able to invest the proceeds in other investments providing as high a level of income, resulting in a reduced yield to the Fund. In the case of mortgage- or other asset-backed securities, as interest rates decrease or spreads narrow, the likelihood of prepayment increases. Conversely, extension risk is the risk that an unexpected rise in interest rates will extend the life of a mortgage- or other asset-backed security beyond the prepayment time. If the Fund’s investments are locked in at a lower interest rate for a longer period of time, the portfolio managers may be unable to capitalize on securities with higher interest rates or wider spreads.

Reinvestment Risk. Reinvestment risk arises when the Fund is unable to reinvest income or principal at the same return it is currently earning.

Rule 144A and Other Exempted Securities Risk. The Fund may invest in privately placed and other securities or instruments exempt from SEC registration (collectively “private placements”), subject to liquidity and other regulatory restrictions. In the U.S. market, private placements are typically sold only to qualified institutional buyers, or qualified purchasers, as applicable. An insufficient number of buyers interested in purchasing private placements at a particular time could adversely affect the marketability of such investments and the Fund might be unable to dispose of them promptly or at reasonable prices, subjecting the Fund to liquidity risk. The Fund may invest in private placements determined to be liquid as well as those determined to be illiquid. Even if determined to be liquid, the Fund’s holdings of private placements may increase the level of Fund illiquidity if eligible buyers are unable or unwilling to purchase them at a particular time. Issuers of Rule 144A eligible securities are required to furnish information to potential investors upon request. However, the required disclosure is much less extensive than that required of public companies and is not publicly available since the offering is not filed with the SEC. Further, issuers of Rule 144A eligible securities can require recipients of the offering information (such as the Fund) to agree contractually to keep the information confidential, which could also adversely affect the Fund’s ability to dispose of the security.

Secondary Market Trading Risk. Investors buying or selling Fund shares will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of Fund shares.

Sector Risk. At times, the Fund may have a significant portion of its assets invested in securities of companies conducting business within one or more economic sectors. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Sovereign Debt Risk. A sovereign debtor’s willingness or ability to repay principal and pay interest in a timely manner may be affected by a variety of factors, including its cash flow situation, the extent of its reserves, the availability of sufficient foreign exchange on the date a payment is due, the relative size of the debt service burden to the economy as a whole, the sovereign debtor’s policy toward international lenders, and the political constraints to which a sovereign debtor may be subject.

U.S. Government Obligations Risk. While U.S. Treasury obligations are backed by the “full faith and credit” of the U.S. Government, such securities are nonetheless subject to credit risk (i.e., the risk that the U.S. Government may be, or be perceived to be, unable or unwilling to honor its financial obligations, such as making payments). Securities issued or guaranteed by federal agencies or authorities and U.S. Government-sponsored instrumentalities or enterprises may or may not be backed by the full faith and credit of the U.S. Government.

Valuation Risk. The sales price the Fund could receive for any particular investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair value methodology that produces an estimate of the fair value of the security/instrument, which may prove to be inaccurate.

Prospectus 2019

11

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund (continued)

  

12	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

Summary of the Fund (continued)

Purchase and Sale of Fund Shares

The Fund issues and redeems shares only through Authorized Participants (typically broker-dealers) in large blocks of shares, typically 50,000 shares, called Creation Units. Creation Units are issued and redeemed typically for an in-kind basket of securities. Individual shares may only be purchased and sold on a national securities exchange through a broker-dealer. Because the Fund’s shares trade at market prices rather than NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount).

Tax Information

Distributions you receive from the Fund are taxed as ordinary income for federal income tax purposes, except to the extent designated as net capital gain, qualified dividend or return of capital and may also be subject to state or local taxes, unless you are investing through a tax-advantaged retirement plan account or are a tax-exempt investor.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your financial advisor to recommend the Fund over another investment. Ask your financial advisor or visit your financial intermediary’s website for more information.

Prospectus 2019

13

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

Association (FNMA) and Federal Home Loan Mortgage Corporation (FHLMC)) that meet the following criteria: have a 30-year fixed-rate program, an issuance date less than 1,000 days, and that are denominated in U.S. dollars. At January 31, 2019, this sector index model held 28 securities.

Beta Advantage ^® Strategy to Investing in the U.S. Corporate Investment Grade Debt Sector. As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the Bloomberg Barclays US Corporate Total Return Index (which is comprised of investment grade, fixed-rate, taxable, U.S. dollar denominated debt with $250 million or more of par amount outstanding, issued by U.S. and non-U.S. industrial companies, utilities, and financial institutions) that meet the following criteria: have a remaining maturity of between and including 5 to 15 years, a credit rating between and including BAA1 and BAA3 using the Bloomberg Barclays index rating methodology, and an issuance date not greater than 1,000 days. The two largest issues from each issuer are selected based on amount outstanding. At January 31, 2019, this sector index model held 504 securities.

Beta Advantage ^® Strategy to Investing in the U.S. Corporate High Yield Debt Sector . As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the Bloomberg Barclays US Corporate High Yield Total Return Index (which is comprised of publicly issued U.S. dollar denominated, non-investment grade, fixed-rate, taxable corporate bonds) that meet the following criteria: have a (non-investment grade) credit rating above B3 using the Bloomberg index rating methodology, an outstanding face amount greater than $800 million, remaining maturity of less than 14 years, and issued within the past 5 years. Pay-in-kind (PIK) and partial PIK instruments are excluded from this sector index model. The two largest issues from each issuer are selected based on amount outstanding, subject to a 2% issuer cap based on market value. At January 31, 2019, this sector index model held 177 securities.

Beta Advantage ^® Strategy to Investing in the Emerging Markets Sovereign and Quasi-Sovereign Debt Sector . As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the Bloomberg Barclays Emerging Markets USD Aggregate Total Return Index (which is comprised of fixed-rate sovereign and quasi-sovereign debt of emerging market countries rated investment grade and non-investment grade) that meet the following criteria, with corporate issuers being excluded: have a credit rating between and including BAA1 and BA3 using the Bloomberg Barclays index rating methodology, remaining maturity of between and including 5 to 15 years, and a minimum amount outstanding of at least $2 billion. The two largest issues from each issuer are selected based on amount outstanding, subject to a maximum 10% country weighting (based on market value). At January 31, 2019, this sector index model held 62 securities.

The Fund may invest, as part of its 80% investment policy or otherwise when the Investment Manager believes it will help the Fund track the Index, in privately placed and other securities or instruments that are purchased and sold pursuant to Rule 144A or other exemptions under the Securities Act of 1933, as amended (the 1933 Act), subject to liquidity determinations and certain regulatory restrictions.

The Index (as well as the six sector index models) are reconstituted and rebalanced monthly on the last business day of each month.

As noted above, the six sector index models will generate all of the component securities of the Index. Columbia Management expects to utilize a “representative sampling” strategy whereby the Fund invests in only some of the component securities of the Index that, collectively, are believed by the Investment Manager to generally reflect the same risk and return characteristics of the Index. As such, the Fund may not track the Index with the same degree of accuracy as would an investment vehicle replicating (or investing in) the entire Index. Through its representative sampling investment technique, the Fund expects to typically hold 200 to 250 holdings, which is a subset of the total number of holdings in the Index, which, as of January 31, 2019, had 180 holdings. There may be instances in which the Fund may overweight (or underweight) an Index holding, purchase (or sell) instruments not in the Index as a substitute for one or more securities in the Index or utilize various combinations of other available investment techniques in seeking to replicate the performance of the Index. Under certain circumstances or conditions or due to other factors, including, for example, the size of the Fund (in terms of assets under management), the Fund may increase its number of holdings beyond the typical range of holdings stated above.

Prospectus 2019

15

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

The Fund may sell securities or other holdings that are represented in the Index or purchase securities or make other investments that are not yet represented in the Index in anticipation of their removal from or addition to the Index by the Index Provider.

The Investment Manager does not invest the Fund’s assets based on its view of the investment merits of a particular security or company, neither does it conduct fundamental investment research or analysis, nor seek to forecast or otherwise consider market movements, conditions or trends in managing the Fund’s assets. The Fund pursues its investment objective of correlating performance with the Index regardless of market conditions and does not take defensive positions.

To the extent the Index is concentrated in a particular sector or industry, the Fund will necessarily be concentrated in that sector or industry.

The Fund’s investment policy with respect to 80% of its assets may be changed by the Fund’s Board of Trustees without shareholder approval as long as shareholders are given 60 days’ advance written notice of the change. Additionally, shareholders will be given 60 days’ notice of any change to the Fund’s investment objective made to comply with the SEC rule governing investment company names.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Authorized Participant Concentration Risk. Only an Authorized Participant (as defined below) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units, Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund share level and at the Fund holdings level.

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.

Concentration Risk. The Fund will concentrate its investments in companies conducting business in a related group of industries within a sector(s) to approximately the same extent as the Index. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly a fund diversifies its investments, the more it spreads risk and potentially reduces the risks of loss and volatility.

Correlation/Tracking Error Risk. The Fund’s value will generally decline when the performance of the Index declines. A number of factors may affect the Fund’s ability to achieve a high degree of correlation with the Index, and there is no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation may prevent the Fund from achieving its investment objective. The factors that may adversely affect the Fund’s correlation with the Index include, among others, the size of the Fund’s portfolio, fees, expenses, transaction costs, income items, valuation methodology, accounting standards, the effectiveness of sampling techniques, changes in the Index and disruptions or illiquidity in the markets for the securities or other instruments in which the Fund invests. The Fund uses a “representative sampling” approach in seeking to track the performance of the Index, which is an indexing strategy that involves investing in only some of the components of the Index that collectively have an investment profile similar to that of the Index. Because the Fund uses a representative sampling approach, the Fund

16	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

may not track the Index with the same degree of accuracy as would an investment vehicle replicating the entire Index. In addition, the Fund may invest in securities or other instruments not included in the Index. The Fund may take or refrain from taking investment positions for various reasons, such as tax efficiency purposes, or to comply with regulatory restrictions, which may negatively affect the Fund’s correlation with the Index. The Fund may also be subject to large movements of assets into and out of the Fund, potentially resulting in the Fund being over- or under-exposed to certain components of the Index and may be impacted by Index reconstitutions and Index rebalancing events. Additionally, the Fund's foreign investments may trade on markets that may not be open on the same day or at the same time as the Fund, which may cause a difference between the changes in the daily performance of the Fund and changes in the level of the Index. Furthermore, the Fund may need to execute currency trades that due to regulatory, legal and operational constraints will occur at a later date than the trading of the related security. Currency holdings may be valued at a different time and at different rates than that used by the Index. Holding cash balances may detract from the Fund’s ability to track the Index. In addition, the Fund’s NAV may deviate from the Index if the Fund fair values a portfolio security at a price other than the price used by the Index for that security. The Fund also bears management and other expenses and transaction costs in trading securities or other instruments, which the Index does not bear. Accordingly, the Fund’s performance will likely fail to match the performance of the Index, after taking expenses into account. Any of these factors could decrease correlation between the performance of the Fund and the Index and may hinder the Fund’s ability to meet its investment objective. It is not possible to invest directly in an index.

Counterparty Risk. The risk exists that a counterparty to a transaction in a financial instrument held by the Fund or by a special purpose or structured vehicle in which the Fund invests may become insolvent or otherwise fail to perform its obligations, including making payments to the Fund, due to financial difficulties. The Fund may obtain no or limited recovery in a bankruptcy or other reorganizational proceedings, and any recovery may be significantly delayed. Transactions that the Fund enters into may involve counterparties in the financial services sector and, as a result, events affecting the financial services sector may cause the Fund’s share value to fluctuate.

Credit Risk. Credit risk is the risk that the value of debt instruments may decline if the borrower or the issuer thereof defaults or otherwise becomes unable or unwilling, or is perceived to be unable or unwilling, to honor its financial obligations, such as making payments to the Fund when due. Various factors could affect the actual or perceived willingness or ability of the borrower or the issuer to make timely interest or principal payments, including changes in the financial condition of the borrower or the issuer or in general economic conditions. Rating agencies assign credit ratings to certain debt instruments to indicate their credit risk. Unless otherwise provided in the Fund’s Principal Investment Strategies, investment grade debt instruments are those rated at or above BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. Conversely, below investment grade (commonly called “high-yield” or “junk”) debt instruments are those rated below BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. A rating downgrade by such agencies can negatively impact the value of such instruments. Lower quality or unrated instruments held by the Fund may present increased credit risk as compared to higher-rated instruments. Non-investment grade debt instruments may be subject to greater price fluctuations and are more likely to experience a default than investment grade debt instruments and therefore may expose the Fund to increased credit risk. If the Fund purchases unrated instruments, or if the ratings of instruments held by the Fund are lowered after purchase, the Fund will depend on analysis of credit risk more heavily than usual. If the issuer of a loan declares bankruptcy or is declared bankrupt, there may be a delay before the Fund can act on the collateral securing the loan, which may adversely affect the Fund. Further, there is a risk that a court could take action with respect to a loan that is adverse to the holders of the loan. Such actions may include invalidating the loan, the lien on the collateral, the priority status of the loan, or ordering the refund of interest previously paid by the borrower. Any such actions by a court could adversely affect the Fund’s performance. A default or expected default of a loan could also make it difficult for the Fund to sell the loan at a price approximating the value previously placed on it. In order to enforce its rights in the event of a default, bankruptcy or similar situation, the Fund may be required to retain legal or similar counsel. This may increase the Fund’s operating expenses and adversely affect its NAV. Loans that have a lower priority for repayment in an issuer’s capital structure may involve a higher degree of overall risk than more senior loans of the same borrower.

Prospectus 2019

17

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

Depositary Receipts Risk. Depositary receipts are receipts issued by a bank or trust company reflecting ownership of underlying securities issued by foreign companies. Some foreign securities are traded in the form of American Depositary Receipts and/or Global Depositary Receipts. Depositary receipts involve risks similar to the risks associated with investments in foreign securities, including those associated with investing in the particular country of an issuer, which may be related to the particular political, regulatory, economic, social and other conditions or events, including, for example, military confrontations, war and terrorism, occurring in the country and fluctuations in such country’s currency, as well as market risk tied to the underlying foreign company. In addition, holders of depositary receipts may have limited voting rights, may not have the same rights afforded to stockholders of a typical domestic company in the event of a corporate action, such as an acquisition, merger or rights offering, and may experience difficulty in receiving company stockholder communications. There is no guarantee that a financial institution will continue to sponsor a depositary receipt, or that a depositary receipt will continue to trade on an exchange, either of which could adversely affect the liquidity, availability and pricing of the depositary receipt. Changes in foreign currency exchange rates will affect the value of depositary receipts and, therefore, may affect the value of your investment in the Fund. To the extent that the exchange price of a depositary receipt differs from the local price of the underlying security used by the Index, the Fund may be prevented from fully achieving its investment objective of tracking the performance of the Index.

Early Close/Late Close/Trading Halt Risk.  An exchange or market may close early, close late or issue trading halts on specific securities, or the ability to buy or sell certain securities may be restricted, which may result in the Fund being unable to buy or sell these securities. In these circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments, may incur substantial trading losses and/or may be prevented from sufficiently tracking the performance of the Index.

Emerging Market Securities Risk. Securities issued by foreign governments or companies in emerging market countries are more likely to have greater exposure to the risks of investing in foreign securities that are described in Foreign Securities Risk. In addition, emerging market countries are more likely to experience instability resulting, for example, from rapid changes or developments in social, political, economic or other conditions. Their economies are usually less mature and their securities markets are typically less developed with more limited trading activity ( i.e. , lower trading volumes and less liquidity) than more developed countries. Emerging market securities tend to be more volatile than securities in more developed markets. Many emerging market countries are heavily dependent on international trade and have fewer trading partners, which makes them more sensitive to world commodity prices and economic downturns in other countries. Some emerging market countries have a higher risk of currency devaluations, and some of these countries may experience periods of high inflation or rapid changes in inflation rates and may have hostile relations with other countries.

Foreign Currency Risk. The performance of the Fund may be materially affected positively or negatively by foreign currency strength or weakness relative to the U.S. dollar, particularly if the Fund invests a significant percentage of its assets in foreign securities or other assets denominated in currencies other than the U.S. dollar. Currency rates in foreign countries may fluctuate significantly over short or long periods of time for a number of reasons, including changes in interest rates, imposition of currency controls and economic or political developments in the U.S. or abroad. The Fund may also incur currency conversion costs when converting foreign currencies into U.S. dollars and vice versa. Restrictions on currency trading may be imposed by foreign countries, which may adversely affect the value of your investment in the Fund. Even though the currencies of some countries may be pegged to the U.S. dollar, the conversion rate may be controlled by government regulation or intervention at levels significantly different than what would normally prevail in a free market. Significant revaluations of the U.S. dollar exchange rate of these currencies could cause substantial reductions in the Fund’s NAV.

Foreign Securities Risk. Investments in or exposure to foreign securities involve certain risks not associated with investments in or exposure to securities of U.S. companies. For example, foreign markets can be extremely volatile. Foreign securities may also be less liquid than securities of U.S. companies so that the Fund may, at times, be unable to sell foreign securities at desirable times or prices. Brokerage commissions, custodial costs and other fees are also generally higher for foreign securities. The Fund may have limited or no legal recourse in the event of default with respect to certain foreign securities, including those issued by foreign governments. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the

18	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

disposition of foreign securities, which could reduce the Fund’s return on such securities. In some cases, such withholding or other taxes could potentially be confiscatory. Other risks include: possible delays in the settlement of transactions or in the payment of income; generally less publicly available information about foreign companies; the impact of economic, political, social, diplomatic or other conditions or events (including, for example, military confrontations, war and terrorism), possible seizure, expropriation or nationalization of a company or its assets or the assets of a particular investor or category of investors; accounting, auditing and financial reporting standards that may be less comprehensive and stringent than those applicable to domestic companies; the imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country; and the generally less stringent standard of care to which local agents may be held in the local markets. In addition, it may be difficult to obtain reliable information about the securities and business operations of certain foreign issuers. Governments or trade groups may compel local agents to hold securities in designated depositories that are not subject to independent evaluation. The less developed a country’s securities market is, the greater the level of risks. The risks posed by sanctions against a particular foreign country, its nationals or industries or businesses within the country may be heightened to the extent the Fund invests significantly in the affected country or region or in issuers from the affected country that depend on global markets. Additionally, investments in certain countries may subject the Fund to a number of tax rules, the application of which may be uncertain. Countries may amend or revise their existing tax laws, regulations and/or procedures in the future, possibly with retroactive effect. Changes in or uncertainties regarding the laws, regulations or procedures of a country could reduce the after-tax profits of the Fund, directly or indirectly, including by reducing the after-tax profits of companies located in such countries in which the Fund invests, or result in unexpected tax liabilities for the Fund. The performance of the Fund may also be negatively affected by fluctuations in a foreign currency's strength or weakness relative to the U.S. dollar, particularly to the extent the Fund invests a significant percentage of its assets in foreign securities or other assets denominated in currencies other than the U.S. dollar. Currency rates in foreign countries may fluctuate significantly over short or long periods of time for a number of reasons, including changes in interest rates, imposition of currency exchange controls and economic or political developments in the U.S. or abroad. The Fund may also incur currency conversion costs when converting foreign currencies into U.S. dollars and vice versa. Additionally, the Fund’s foreign investments may trade in markets that may not be open on the same day or at the same time as the Fund, or foreign markets may close after the Fund has calculated its NAV for a given business day, which may cause a difference in the market price of such foreign securities and the value attributed to such securities by the Fund.

Forward Commitments on Mortgage-Backed Securities (including Dollar Rolls) Risk. When purchasing mortgage-backed securities in the “to be announced” (TBA) market (MBS TBAs), the seller agrees to deliver mortgage-backed securities for an agreed upon price on an agreed upon date, but may make no guarantee as to the specific securities to be delivered. In lieu of taking delivery of mortgage-backed securities, the Fund could enter into dollar rolls, which are transactions in which the Fund sells securities to a counterparty and simultaneously agrees to purchase those or similar securities in the future at a predetermined price. Dollar rolls involve the risk that the market value of the securities the Fund is obligated to repurchase may decline below the repurchase price, or that the counterparty may default on its obligations. These transactions may also increase the Fund’s portfolio turnover rate. If the Fund reinvests the proceeds of the security sold, the Fund will also be subject to the risk that the investments purchased with such proceeds will decline in value (a form of leverage risk). MBS TBAs and dollar rolls are subject to the risk that the counterparty to the transaction may not perform or be unable to perform in accordance with the terms of the instrument.

Fund Shares Liquidity Risk. Although the Fund’s shares are listed on the Exchange, there can be no assurance that an active, liquid or otherwise orderly trading market for shares will be established or maintained by market makers or Authorized Participants, particularly in times of stressed market conditions. In this regard, there is no obligation for market makers to make a market in the Fund’s shares or for Authorized Participants to submit purchase or redemption orders for creation units. Accordingly, if such parties determine not to perform their respective roles, this could, in turn, lead to variances between the market price of the Fund’s shares and the underlying value of those shares. Trading in Fund shares on the Exchange also may be disrupted or even halted due to market conditions or for reasons that, in the view of the Exchange, make trading in Fund shares inadvisable. In addition, trading in Fund

Prospectus 2019

19

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

shares on the Exchange may be subject to trading halts caused by extraordinary market volatility pursuant to the Exchange “circuit breaker” rules. There also can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund’s shares will continue to be met or will remain unchanged.

High-Yield Investments Risk. Securities and other debt instruments held by the Fund that are rated below investment grade (commonly called “high-yield” or “junk” bonds) and unrated debt instruments of comparable quality tend to be more sensitive to credit risk than higher-rated debt instruments and may experience greater price fluctuations in response to perceived changes in the ability of the issuing entity or obligor to pay interest and principal when due than to changes in interest rates. These investments are generally more likely to experience a default than higher-rated debt instruments. High-yield debt instruments are considered to be predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal. These debt instruments typically pay a premium – a higher interest rate or yield – because of the increased risk of loss, including default. High-yield debt instruments may require a greater degree of judgment to establish a price, may be difficult to sell at the time and price the Fund desires, may carry high transaction costs, and also are generally less liquid than higher-rated debt instruments. The ratings provided by third party rating agencies are based on analyses by these ratings agencies of the credit quality of the debt instruments and may not take into account every risk related to whether interest or principal will be timely repaid. In adverse economic and other circumstances, issuers of lower-rated debt instruments are more likely to have difficulty making principal and interest payments than issuers of higher-rated debt instruments.

Index Methodology Risk. The Fund seeks performance that corresponds to the performance of the Index. There is no guarantee or assurance that the Index will achieve high, or even positive, returns. The Index may underperform more traditional indices. The Fund could lose value while other indices or measures of market performance increase in value or performance. In addition, the Fund may be subject to the risk that the index provider may not follow its stated methodology for construction of the Index and/or achieve the index provider’s intended performance objective. Errors may result in a negative performance impact to the Fund and its shareholders.

Interest Rate Risk. Interest rate risk is the risk of losses attributable to changes in interest rates. In general, if prevailing interest rates rise, the values of debt instruments tend to fall, and if interest rates fall, the values of debt instruments tend to rise. Changes in the value of a debt instrument usually will not affect the amount of income the Fund receives from it but will generally affect the value of your investment in the Fund. Changes in interest rates may also affect the liquidity of the Fund’s investments in debt instruments. In general, the longer the maturity or duration of a debt instrument, the greater its sensitivity to changes in interest rates. Interest rate declines also may increase prepayments of debt obligations, which, in turn, would increase prepayment risk (the risk that the Fund will have to reinvest the money received in securities that have lower yields). Similarly, a period of rising interest rates may negatively impact the Fund’s performance. Actions by governments and central banking authorities can result in increases in interest rates. Such actions may negatively affect the value of debt instruments held by the Fund, resulting in a negative impact on the Fund's performance and NAV. Debt instruments with floating coupon rates are typically less sensitive to interest rate changes, but these debt instruments may decline in value if their coupon rates do not rise as much as, or keep pace with, yields on such types of debt instruments. Because rates on certain floating rate loans and other debt instruments reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause fluctuations in the Fund’s NAV. Any interest rate increases could cause the value of the Fund’s investments in debt instruments to decrease. Rising interest rates may prompt redemptions from the Fund, which may force the Fund to sell investments at a time when it is not advantageous to do so, which could result in losses.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors.

Limitations of Intraday Indicative Value (IIV) Risk. The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the

20	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

business day, (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close, which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. For example, if the Fund fair values portfolio securities, the Fund’s NAV may deviate from the approximate per share value of the Fund’s published basket of portfolio securities (i.e., the IIV), which could result in the market prices for Fund shares deviating from NAV. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions of creation units, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market. In certain circumstances, the Fund might not be able to dispose of certain holdings quickly or at fair prices, preventing the Fund from tracking the Index. Foreign securities can present enhanced liquidity risks, including as a result of less developed custody, settlement or other practices of foreign markets. In addition, in stressed market conditions, the market for Fund shares may become less liquid. Deterioration in the liquidity of Fund shares may adversely impact the liquidity of the Fund's underlying portfolio securities. These adverse impacts on the liquidity of Fund shares and on the liquidity of the Fund's underlying portfolio securities could in turn lead to differences between the market price of Fund shares and the underlying value of those shares.

Market Price Relative to NAV Risk. Shares of the Fund may trade at prices that vary from Fund NAV. Shares of the Fund are listed for trading on the Exchange and are bought and sold in the secondary market at market prices that may differ, in some cases significantly, from their NAV. The NAV of the Fund will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of shares, however, will generally fluctuate in response to changes in NAV, as well as the relative supply of, and demand for, Fund shares on the Exchange. The Investment Manager cannot predict whether Fund shares will trade below, at or above their NAV. Price differences may result because of, among other factors, supply and demand forces in the secondary trading market for Fund shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings. In this connection, if a shareholder purchases Fund shares at a time when the market price is at a premium to the NAV or sells shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses. Different investment strategies or techniques, including those intended to be defensive in nature, including, as examples, stop loss orders to sell an ETF’s shares in the secondary market during negative market events or conditions, such as a “flash crash” or other market disruptions may not work as intended and may produce significant losses to investors. Investors should consult their financial intermediary prior to using any such investment strategies or techniques, or before investing in the Fund.

Prospectus 2019

21

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. The value of Fund investments may fall or fail to rise because of a variety of actual or perceived factors affecting an issuer (e.g., unfavorable news), the industry or sector in which it operates, or the market as a whole, which may reduce the value of an investment in the Fund. Accordingly, an investment in the Fund could lose money over short or long periods. The market values of the investments the Fund holds can be affected by changes or potential or perceived changes in U.S. or foreign economies, financial markets, interest rates and the liquidity of these investments, among other factors.

Mortgage-Backed Securities Risk. The value of any mortgage-backed securities held by the Fund may be affected by, among other things, changes or perceived changes in: interest rates; factors concerning the interests in and structure of the issuer or the originator of the mortgages; the creditworthiness of the entities that provide any supporting letters of credit, surety bonds or other credit enhancements; or the market's assessment of the quality of underlying assets. Mortgage-backed securities represent interests in, or are backed by, pools of mortgages from which payments of interest and principal (net of fees paid to the issuer or guarantor of the securities) are distributed to the holders of the mortgage-backed securities. Mortgage--backed securities can have a fixed or an adjustable rate. Mortgage--backed securities are subject to liquidity risk (the risk that it may not be possible for the Fund to liquidate the instrument at an advantageous time or price) and prepayment risk (the risk that the underlying mortgage may be refinanced or prepaid prior to maturity during periods of declining or low interest rates, causing the Fund to have to reinvest the money received in securities that have lower yields). In addition, the impact of prepayments on the value of mortgage--backed securities may be difficult to predict and may result in greater volatility. A decline or flattening of housing values may cause delinquencies in the mortgages (especially sub-prime or non-prime mortgages) underlying mortgage-backed securities and thereby adversely affect the ability of the mortgage-backed securities issuer to make principal and/or interest payments to mortgage-backed securities holders, including the Fund. Rising or high interest rates tend to extend the duration of mortgage--backed securities, making them more volatile and more sensitive to changes in interest rates. Payment of principal and interest on some mortgage-backed securities (but not the market value of the securities themselves) may be guaranteed (i) by the full faith and credit of the U.S. Government (in the case of securities guaranteed by the Government National Mortgage Association) or (ii) by its agencies, authorities, enterprises or instrumentalities (in the case of securities guaranteed by the Federal National Mortgage Association (FNMA) or the Federal Home Loan Mortgage Corporation (FHLMC)), which are not insured or guaranteed by the U.S. Government (although FNMA and FHLMC may be able to access capital from the U.S. Treasury to meet their obligations under such securities). Mortgage-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) may be supported by various credit enhancements, such as pool insurance, guarantees issued by governmental entities, letters of credit from a bank or senior/subordinated structures, and may entail greater risk than obligations guaranteed by the U.S. Government, whether or not such obligations are guaranteed by the private issuer.

Passive Investment Risk. The Fund is not “actively” managed and may be affected by a general decline in market segments related to its underlying index. The Fund invests in securities or instruments included in, or believed by the Investment Manager to be representative of, its underlying index, regardless of their investment merits. The Fund does not seek temporary defensive positions when markets decline or appear overvalued. The decision of whether to remove a security from an index is made by an independent index provider who is not affiliated with the Fund or the Investment Manager.

Portfolio Turnover Risk. The Fund may pay transaction costs, such as commissions and/or spreads, when it buys and sells securities or other holdings (or “turns over” its portfolio). High levels of transactions increase brokerage and other transaction costs and may result in increased taxable capital gains.

Prepayment and Extension Risk. Prepayment and extension risk is the risk that a loan, bond or other security or investment might, in the case of prepayment risk, be called or otherwise converted, prepaid or redeemed before maturity and, in the case of extension risk, that the investment might not be called as expected. In the case of prepayment risk, if the investment is converted, prepaid or redeemed before maturity, the portfolio managers may not be able to invest the proceeds in other investments providing as high a level of income, resulting in a reduced yield to the Fund. In the case of mortgage- or other asset-backed securities, as interest rates decrease or spreads

22	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

narrow, the likelihood of prepayment increases. Conversely, extension risk is the risk that an unexpected rise in interest rates will extend the life of a mortgage- or other asset-backed security beyond the prepayment time. If the Fund's investments are locked in at a lower interest rate for a longer period of time, the portfolio managers may be unable to capitalize on securities with higher interest rates or wider spreads.

Reinvestment Risk. Reinvestment risk arises when the Fund is unable to reinvest income or principal at the same return it is currently earning.

Rule 144A and Other Exempted Securities Risk. The Fund may invest in privately placed and other securities or instruments exempt from SEC registration (collectively “private placements”), subject to liquidity and other regulatory restrictions. In the U.S. market, private placements are typically sold only to qualified institutional buyers, or qualified purchasers, as applicable. An insufficient number of buyers interested in purchasing private placements at a particular time could adversely affect the marketability of such investments and the Fund might be unable to dispose of them promptly or at reasonable prices, subjecting the Fund to liquidity risk (the risk that it may not be possible for the Fund to liquidate the instrument at an advantageous time or price). The Fund may invest in private placements determined to be liquid as well as those determined to be illiquid. Even if determined to be liquid, the Fund’s holdings of private placements may increase the level of Fund illiquidity if eligible buyers are unable or unwilling to purchase them at a particular time. The Fund may also have to bear the expense of registering the securities for resale and the risk of substantial delays in effecting the registration. Additionally, the purchase price and subsequent valuation of private placements typically reflect a discount, which may be significant, from the market price of comparable securities for which a more liquid market exists. Issuers of Rule 144A eligible securities are required to furnish information to potential investors upon request. However, the required disclosure is much less extensive than that required of public companies and is not publicly available since the offering is not filed with the SEC. Further, issuers of Rule 144A eligible securities can require recipients of the offering information (such as the Fund) to agree contractually to keep the information confidential, which could also adversely affect the Fund’s ability to dispose of the security.

Secondary Market Trading Risk. Investors buying or selling Fund shares will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of shares. In addition, secondary market investors will also incur the cost of the difference between the price that an investor is willing to pay for Fund shares (the bid price) and the price at which an investor is willing to sell Fund shares (the ask price). This difference in bid and ask prices is often referred to as the “spread” or “bid/ask spread.” The bid/ask spread varies over time for Fund shares based on trading volume and market liquidity, and is generally lower if the Fund’s shares have more trading volume and market liquidity and higher if the Fund’s shares have little trading volume and market liquidity. Further, increased market volatility may cause increased bid/ask spreads.

Sector Risk. At times, the Fund may have a significant portion of its assets invested in securities of companies conducting business within one or more economic sectors. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Sovereign Debt Risk. A sovereign debtor’s willingness or ability to repay principal and pay interest in a timely manner may be affected by a variety of factors, including its cash flow situation, the extent of its reserves, the availability of sufficient foreign exchange on the date a payment is due, the relative size of the debt service burden to the economy as a whole, the sovereign debtor’s policy toward international lenders, and the political constraints to which a sovereign debtor may be subject.

With respect to sovereign debt of emerging market issuers, investors should be aware that certain emerging market countries are among the largest debtors to commercial banks and foreign governments. At times, certain emerging market countries have declared moratoria on the payment of principal and interest on external debt. Certain emerging market countries have experienced difficulty in servicing their sovereign debt on a timely basis and that has led to defaults and the restructuring of certain indebtedness to the detriment of debt-holders.

Prospectus 2019

23

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

U.S. Government Obligations Risk. While U.S. Treasury obligations are backed by the “full faith and credit” of the U.S. Government, such securities are nonetheless subject to credit risk ( i.e. , the risk that the U.S. Government may be, or may be perceived to be, unable or unwilling to honor its financial obligations, such as making payments). Securities issued or guaranteed by federal agencies or authorities and U.S. Government-sponsored instrumentalities or enterprises may or may not be backed by the full faith and credit of the U.S. Government. For example, securities issued by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association and the Federal Home Loan Banks are neither insured nor guaranteed by the U.S. Government. These securities may be supported by the ability to borrow from the U.S. Treasury or only by the credit of the issuing agency, authority, instrumentality or enterprise and, as a result, are subject to greater credit risk than securities issued or guaranteed by the U.S. Treasury.

Valuation Risk. The sales price the Fund could receive for any particular investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair value methodology that produces an estimate of the fair value of the security/instrument, which may prove to be inaccurate.

How the Fund Differs from Traditional Mutual Funds

Redeemability. Traditional mutual fund shares may be bought from, and redeemed with, the issuing fund for cash at NAV typically calculated once at the end of each business day. Shares of the Fund, by contrast, cannot be purchased from or redeemed with the Fund except by or through Authorized Participants (defined below), and then typically for an in-kind basket of securities. In addition, the Fund issues and redeems shares on a continuous basis only in large blocks of shares, typically 50,000 shares, called Creation Units.

As an ETF, the Fund intends to rely on an exemptive order issued by the SEC to the Trust that permits the Fund to delay payment of redemption proceeds for its securities for up to 14 calendar days, based in part on the greater relative illiquidity and longer settlement times of emerging market securities. This risk applies to investors such as market makers, large investors and institutions who purchase and sell Creation Units directly from and to the Fund and does not apply to investors who will buy and sell shares of the Fund in secondary market transactions on the Exchange through brokers.

Exchange Listing. Unlike traditional mutual fund shares, the Fund’s shares are listed for trading on the Exchange. Investors can purchase and sell shares on the secondary market through a broker or other financial intermediary (collectively, financial intermediary(ies)). There can be no assurance that the Fund's shares will continue to trade on the Exchange or that the Fund's shares will continue to meet the requirements for listing or trading on the Exchange. See "Fund Shares Liquidity Risk" above. Investors purchasing shares in the secondary market through a brokerage account or with the assistance of a financial intermediary may be subject to brokerage commissions and charges. Secondary-market transactions do not occur at NAV, but at market prices that change throughout the day, based on the supply of, and demand for, shares and on changes in the prices of the Fund’s portfolio holdings. The market price of shares may differ from the NAV of the Fund. The difference between market price of shares and the NAV of the Fund is called a premium when the market price is above the reported NAV and called a discount when the market price is below the reported NAV. The market price of the Fund's shares may deviate significantly from the NAV of the shares, for example, in times of extreme market volatility or other conditions.

Tax Treatment. The Fund’s structure may provide for enhanced tax efficiency relative to a traditional mutual fund’s structure. Specifically, to the extent the Fund redeems its shares in kind, the distribution of portfolio securities to meet such redemption requests may mitigate certain adverse tax consequences associated with traditional mutual fund shares to continuing Fund shareholders. This is because traditional mutual funds typically sell portfolio securities to obtain cash to meet redemptions and, as necessary, may recognize taxable gains in connection with such sales. By contrast, to the extent the Fund redeems its shares in kind, as opposed to in cash, the Fund’s in-kind redemption mechanism will potentially reduce, relative to a traditional mutual fund, taxable gains resulting from redemptions. However, the Fund cannot predict to what extent, if any, it will redeem its shares in kind rather than in cash, particularly during the Fund’s growth stages when portfolio changes are more likely to be implemented within the Fund rather than through the in-kind redemption mechanism. Nor can the Fund predict the extent to which any such in-kind redemptions will reduce the taxable gain recognized in connection therewith.

24	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

ETFs generally are able to make in-kind redemptions and avoid being taxed on gain on the distributed portfolio securities at the Fund level. Because the Fund may effect redemptions partly or entirely in cash, rather than in-kind distributions, it may be required to sell portfolio securities in order to obtain the cash needed to distribute redemption proceeds. If the Fund recognizes gain on these sales, this generally will cause the Fund to recognize gain it might not otherwise have recognized, or to recognize such gain sooner than would otherwise be required if it were to distribute portfolio securities in-kind. The Fund generally intends to distribute these gains to shareholders to avoid being taxed on this gain at the Fund level and otherwise comply with the special tax rules that apply to it. This strategy may cause shareholders to be subject to tax on gains they would not otherwise be subject to, or at an earlier date than, if they had made an investment in a different ETF. Moreover, cash transactions may have to be carried out over several days if the securities market is relatively illiquid and may involve considerable brokerage fees and taxes. These brokerage fees and taxes, which will be higher than if the Fund sold and redeemed its shares principally in-kind, will be passed on to purchasers and redeemers of Creation Units in the form of creation and redemption transaction fees.

Additional Investment Strategies and Policies

This section describes certain investment strategies and policies that the Fund may utilize in pursuit of its investment objective and some additional factors and risks involved with investing in the Fund.

The Fund may consider changing the Index at any time, including if, for example: the Index becomes unavailable; the Board believes that the Index no longer serves shareholder investment needs or that another index may better serve their needs; or the financial or economic environment makes it difficult for the Fund’s investment results to correspond sufficiently to the Index. If the Fund determines to change the Index, it will assess the appropriateness of the Fund's current name in light of the new index.

20% Asset Policy

In addition to any instruments mentioned in the Fund’s principal investment strategies, the Fund may invest up to 20% of its net assets in derivatives, including forward contracts (including forward foreign currency contracts), futures (including equity futures and index futures), options (including options on futures) and swaps (including portfolio and total return swaps), as well as cash, cash equivalents and money market instruments, such as repurchase agreements and money market funds (including affiliated money market funds), for the purpose of seeking to assist the Fund in tracking the performance of the Index.

Investment Guidelines

As a general matter, and except as specifically described in the discussion of the Fund's principal investment strategies in this prospectus or as otherwise required by the Investment Company Act of 1940, as amended (the 1940 Act), the rules and regulations thereunder and any applicable exemptive relief, whenever an investment policy or limitation states a percentage of the Fund's assets that may be invested in any security or other asset or sets forth a policy regarding an investment standard, compliance with that percentage limitation or standard will be determined solely at the time of the Fund's investment in the security or asset.

Holding Other Kinds of Investments

The Fund may hold other investments that are not part of its principal investment strategies but that are for the purpose of seeking to assist the Fund in tracking the performance of the Index. These investments and their risks are described below and/or in the SAI. The Fund may choose not to invest in certain securities described in this prospectus and in the SAI, although it has the ability to do so. Information on the Fund’s holdings can be found in the Fund’s shareholder reports or by visiting columbiathreadneedleetf.com.

Transactions in Derivatives

The Fund may enter into derivative transactions. Derivatives are financial contracts whose values are, for example, based on (or “derived” from) traditional securities (such as a stock or bond), assets (such as a commodity like gold or a foreign currency), reference rates (such as the London Interbank Offered Rate (commonly known as LIBOR)) or market indices (such as the Standard & Poor's (S&P) 500 ^® Index). The use of derivatives is a highly specialized

Prospectus 2019

25

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

activity which involves investment techniques and risks different from those associated with ordinary portfolio securities transactions. Derivatives involve special risks and may result in losses or may limit the Fund's potential gain from favorable market movements. Derivative strategies often involve leverage, which may exaggerate a loss, potentially causing the Fund to lose more money than it would have lost had it invested in the underlying security or other asset directly. The values of derivatives may move in unexpected ways, especially in unusual market conditions, and may result in increased volatility in the value of the derivative and/or the Fund’s shares, among other consequences. The use of derivatives may also increase the amount of taxes payable by shareholders holding shares in a taxable account. Other risks arise from the Fund's potential inability to terminate or to sell derivative positions. A liquid secondary market may not always exist for the Fund's derivative positions at times when the Fund might wish to terminate or to sell such positions. Over-the-counter instruments (investments not traded on an exchange) may be illiquid, and transactions in derivatives traded in the over-the-counter market are subject to the risk that the other party will not meet its obligations. The use of derivatives also involves the risks of mispricing or improper valuation and that changes in the value of the derivative may not correlate perfectly with the underlying security, asset, reference rate or index. The Fund also may not be able to find a suitable derivative transaction counterparty, and thus may be unable to engage in derivative transactions when it is deemed favorable to do so, or at all. U.S. federal legislation has been enacted that provides for new clearing, margin, reporting and registration requirements for participants in the derivatives market. These changes could restrict and/or impose significant costs or other burdens upon the Fund’s participation in derivatives transactions. For more information on the risks of derivative investments and strategies, see the SAI.

Affiliated Funds Investing in the Fund

The Investment Manager or an affiliate serves as investment adviser to funds using the Columbia brand (Columbia Funds), including those that are structured as “fund-of-funds”, and provides asset-allocation services to (i) shareholders by investing in shares of other Columbia Funds, which may include the Fund (collectively referred to in this section as Underlying Funds), and (ii) discretionary managed accounts (collectively referred to as affiliated products) that invest exclusively in Underlying Funds. These affiliated products, individually or collectively, may own a significant percentage of the outstanding shares of one or more Underlying Funds, and the Investment Manager seeks to balance potential conflicts of interest between the affiliated products and the Underlying Funds in which they invest. The affiliated products’ investment in the Underlying Funds may have the effect of creating economies of scale, possibly resulting in lower expense ratios for the Underlying Funds, because the affiliated products may own substantial portions of the shares of Underlying Funds. However, redemption of Underlying Fund shares by one or more affiliated products could cause the expense ratio of an Underlying Fund to increase, as its fixed costs would be spread over a smaller asset base. Because of large positions of certain affiliated products, the Underlying Funds may experience relatively large inflows and outflows of cash due to affiliated products’ purchases and sales of Underlying Fund shares. Although the Investment Manager or its affiliate may seek to minimize the impact of these transactions where possible, for example, by structuring them over a reasonable period of time or through other measures, Underlying Funds may experience increased expenses as they buy and sell portfolio securities to manage the cash flow effect related to these transactions. Further, when the Investment Manager or its affiliate structures transactions over a reasonable period of time in order to manage the potential impact of the buy and sell decisions for the affiliated products, those affiliated products, including funds-of-funds, may pay more or less (for purchase activity), or receive more or less (for redemption activity), for shares of the Underlying Funds than if the transactions were executed in one transaction. In addition, substantial redemptions by affiliated products within a short period of time could require the Underlying Fund to liquidate positions more rapidly than would otherwise be desirable, which may have the effect of reducing or eliminating potential gain or causing it to realize a loss. In order to meet such redemptions, an Underlying Fund may be forced to sell its liquid (or more liquid) positions, leaving the Underlying Fund holding, post-redemption, a relatively larger position in illiquid investments (i.e., any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment) or less liquid securities. Substantial redemptions may also adversely affect the ability of the Underlying Fund to implement its investment strategy. The Investment Manager or its affiliate also has a conflict of interest in determining the allocation of affiliated products’ assets among the Underlying Funds, as it earns different fees from the various Underlying Funds.

26	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

Investing in Money Market Funds

The Fund may invest cash in, or hold as collateral for certain investments, shares of registered or unregistered money market funds, including funds advised by the Investment Manager or its affiliates. These funds are not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. The Fund and its shareholders indirectly bear a portion of the expenses of any money market fund or other fund in which the Fund may invest.

Fund Website and Disclosure of Portfolio Holdings

Information about the Fund may be found at columbiathreadneedleetf.com. Among other things, this website includes the Summary Prospectus, this prospectus and the SAI, the Fund’s holdings, the Fund’s last annual and semiannual reports, pricing information about shares trading on the Exchange, daily NAV calculations and a historical comparison of the trading prices to NAV.

Each day the Fund is open for business, it publicly disseminates the Fund’s full portfolio holdings as of the close of the previous business day through its website at columbiathreadneedleetf.com. In addition, the In-Kind Creation Basket and In-Kind Redemption Basket, which identify the securities and share quantities which may be delivered in exchange for purchases and redemptions of Creation Units as discussed below and in the SAI, are publicly disseminated each business day prior to the opening of trading on the Exchange via the National Securities Clearing Corporation (NSCC).

Additional Information on Portfolio Turnover

A fund that replaces, or turns over, more than 100% of its investments in a year may be considered to have a high portfolio turnover rate. A high portfolio turnover rate can generate larger distributions of short-term capital gains to shareholders, which for individuals are generally taxable at higher rates than long-term capital gains for U.S. federal income tax purposes. Also, a high portfolio turnover rate can mean higher brokerage commissions and other transaction costs, which could reduce a fund’s returns. In general, the greater the volume of buying and selling by a fund, the greater the impact that brokerage commissions and other transaction costs will have on its returns. The Fund may sell securities regardless of how long they’ve been held. A higher portfolio turnover rate may reduce the relative potential tax efficiency of the Fund compared with traditional mutual funds except potentially in cases where accomplished through redemptions in kind.

Understanding Annual Fund Operating Expenses

The Fund’s annual operating expenses, as presented in the Annual Fund Operating Expenses table in the Fees and Expenses of the Fund section of this prospectus, generally are based on expenses incurred during the Fund’s most recently completed fiscal year and are expressed as a percentage (expense ratio) of the Fund’s average net assets during that fiscal year. The expense ratio reflects the Fund’s fee arrangements as of the date of this prospectus and, unless indicated otherwise, is based on expenses incurred during the Fund’s most recent fiscal year. The Fund’s assets will fluctuate, but unless indicated otherwise in the Annual Fund Operating Expenses table, no adjustments have been or will be made to the expense ratio to reflect any differences in the Fund’s average net assets between the most recently completed fiscal year and the date of this prospectus or a later date. As applicable, any commitment by the Investment Manager and/or its affiliates to waive fees and/or cap (reimburse) expenses is expected, in part, to limit the impact of any increase in the Fund’s expense ratio that would otherwise result because of a decrease in the Fund’s assets in the current fiscal year. The Fund’s annual operating expenses are comprised of (i) investment management fees, (ii) distribution and/or service fees, and (iii) other expenses.

Primary Service Providers

The Fund enters into contractual arrangements (Service Provider Contracts) with various service providers, including, among others, the Investment Manager, the administrator, the distributor, the transfer agent and the Fund’s custodian. The Fund’s Service Provider Contracts are solely among the parties thereto. Shareholders are not parties to, or intended to be third-party beneficiaries of, any Service Provider Contracts. Further, this prospectus, the SAI and any Service Provider Contracts are not intended to give rise to any agreement, duty, special relationship or other obligation between the Fund and any investor, or give rise to any contractual, tort or other rights in any individual

Prospectus 2019

27

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

shareholder, group of shareholders or other person, including any right to assert a fiduciary or other duty, enforce the Service Provider Contracts against the parties or to seek any remedy thereunder, either directly or on behalf of the Fund. Nothing in the previous sentence should be read to suggest any waiver of any rights under federal or state securities laws.

The Investment Manager

Columbia Management Investment Advisers, LLC is located at 225 Franklin Street, Boston, MA 02110 and serves as investment adviser to the Columbia Funds. The Investment Manager is a registered investment adviser and a wholly-owned subsidiary of Ameriprise Financial, Inc. (Ameriprise Financial). The Investment Manager’s management experience covers all major asset classes, including equity securities, debt instruments and money market instruments. In addition to serving as an investment adviser to traditional mutual funds, exchange-traded funds and closed-end funds, the Investment Manager acts as an investment adviser for itself, its affiliates, individuals, corporations, retirement plans, private investment companies and financial intermediaries.

Subject to oversight by the Board, the Investment Manager manages the day-to-day operations of the Fund. The Investment Manager has entered into a license agreement with Bloomberg to use the Beta Advantage ^® Multi-Sector Bond Index, as Bloomberg is the owner of the Index. The Fund is permitted to use the Index pursuant to a sub-licensing agreement with the Investment Manager.

The SEC has issued an order that permits the Investment Manager, subject to the approval of the Board, to appoint an unaffiliated subadviser or to change the terms of a subadvisory agreement, including fees paid thereunder, for the Fund without first obtaining shareholder approval, thereby avoiding the expense and delays typically associated with obtaining shareholder approval. The Investment Manager and its affiliates may have other relationships, including significant financial relationships, with current or potential subadvisers or their affiliates, which may create certain conflicts of interest. When making recommendations to the Board to appoint or to change a subadviser, or to change the terms of a subadvisory agreement, the Investment Manager discloses to the Board the nature of any such material relationships. At present, the Investment Manager has not engaged any investment subadviser for the Fund.

The Fund pays the Investment Manager a fee for its investment advisory services. The fee is calculated as a percentage of the daily net assets of the Fund and is paid monthly. In return for this fee (which is sometimes referred to as a unitary or unified fee), the Investment Manager has agreed to pay the operating costs and expenses of the Fund other than the following expenses, which will be paid by the Fund: taxes, interest incurred on borrowing by the Fund, if any, brokerage fees and commissions,  interest and fee expense related to the Fund’s participation, if any, in inverse floater structures and any other portfolio transaction expenses, infrequent and/or unusual expenses, including without limitation litigation expenses, distribution and/or service fees, expenses incurred in connection with lending securities, and any other expenses approved by the Board. For the Fund’s most recent fiscal year, investment advisory services fees paid to the Investment Manager by the Fund amounted to 0.28% of average daily net assets of the Fund, before any applicable reimbursements.

A discussion regarding the basis for the Board’s approval of the investment management services agreement with the Investment Manager is available in the Fund’s annual report to shareholders for the fiscal period ended October 31, 2017.

Portfolio Managers

Information about the portfolio managers primarily responsible for overseeing the Fund’s investments is shown below. The SAI provides additional information about the portfolio managers, including information relating to compensation, other accounts managed by the portfolio managers, and ownership by the portfolio managers of Fund shares.

    

28	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

Mr. Tannuzzo joined the Investment Manager in 2003. Mr. Tannuzzo began his investment career in 2003 and earned a B.S.B. and an M.B.A. from the University of Minnesota, Carlson School of Management.

Mr. Janssen joined the Investment Manager in 2012. Mr. Janssen began his investment career in 2012 and earned a B.S. from The University of South Dakota and a M.F.M. from the University of Minnesota.

Other Service Providers

ALPS Distributors, Inc. (the Distributor), 1290 Broadway, Suite 1100, Denver, CO 80203, serves as the distributor of Creation Units for the Fund on an agency basis. The Distributor does not maintain a secondary market in shares.

BNY Mellon Corporation (BNY Mellon), 240 Greenwich Street, New York, New York 10286, is the administrator, fund accountant, transfer agent and custodian for the Fund.

PricewaterhouseCoopers LLP, 125 High Street, Boston, MA 02110, serves as the Fund’s independent registered public accounting firm. The independent registered public accounting firm is responsible for auditing the annual financial statements of the Fund.

Index Provider

Bloomberg Index Services Limited, with offices at 731 Lexington Avenue, New York, NY 10022, is the owner and calculator of the Beta Advantage ^® Multi-Sector Bond Index.

Other Roles and Relationships of Ameriprise Financial and its Affiliates — Certain Conflicts of Interest

The Investment Manager provides various services to the Fund and other Columbia Funds for which it is compensated. Ameriprise Financial and its affiliates may also provide other services to these funds and be compensated for them.

The Investment Manager and its affiliates may provide investment advisory and other services to other clients and customers substantially similar to those provided to the Columbia Funds. These activities, and other financial services activities of Ameriprise Financial and its affiliates, may present actual and potential conflicts of interest and introduce certain investment constraints.

Ameriprise Financial is a major financial services company, engaged in a broad range of financial activities beyond the fund-related activities of the Investment Manager, including, among others, insurance, broker-dealer (sales and trading), asset management, banking and other financial activities. These additional activities may involve multiple advisory, financial, insurance and other interests in securities and other instruments, and in companies that issue securities and other instruments, that may be bought, sold or held by the Columbia Funds.

Conflicts of interest and limitations that could affect a Columbia Fund may arise from, for example, the following:

■	compensation and other benefits received by the Investment Manager and other Ameriprise Financial affiliates related to the management/administration of a Columbia Fund and the sale of its shares;

■	the allocation of, and competition for, investment opportunities among the Fund, other funds and accounts advised/managed by the Investment Manager and other Ameriprise Financial affiliates, or Ameriprise Financial itself and its affiliates;

■	separate and potentially divergent management of a Columbia Fund and other funds and accounts advised/managed by the Investment Manager and other Ameriprise Financial affiliates;

■	regulatory and other investment restrictions on investment activities of the Investment Manager and other Ameriprise Financial affiliates and accounts advised/managed by them;

■	insurance and other relationships of Ameriprise Financial affiliates with companies and other entities in which a Columbia Fund invests; and

■	regulatory and other restrictions relating to the sharing of information between Ameriprise Financial and its affiliates, including the Investment Manager, and a Columbia Fund.

Prospectus 2019

29

Columbia Diversified Fixed Income Allocation ETF

More Information About the Fund (continued)

The Investment Manager and Ameriprise Financial have adopted various policies and procedures that are intended to identify, monitor and address conflicts of interest. However, there is no assurance that these policies, procedures and disclosures will be effective.

Additional information about Ameriprise Financial and the types of conflicts of interest and other matters referenced above is set forth in the Investment Management and Other Services — Other Roles and Relationships of Ameriprise Financial and its Affiliates — Certain Conflicts of Interest section of the SAI. Investors in the Columbia Funds should carefully review these disclosures and consult with their financial advisor if they have any questions.

Certain Legal Matters

Ameriprise Financial and certain of its affiliates have historically been involved in a number of legal, arbitration and regulatory proceedings, including routine litigation, class actions and governmental actions, concerning matters arising in connection with the conduct of their business activities. Ameriprise Financial believes that the Fund is not currently the subject of, and that neither Ameriprise Financial nor any of its affiliates are the subject of, any pending legal, arbitration or regulatory proceedings that are likely to have a material adverse effect on the Fund or the ability of Ameriprise Financial or its affiliates to perform under their contracts with the Fund. Information regarding certain pending and settled legal proceedings may be found in the Fund’s shareholder reports and in the SAI. Additionally, Ameriprise Financial is required to make quarterly (10-Q), annual (10-K) and, as necessary, 8-K filings with the SEC on legal and regulatory matters that relate to Ameriprise Financial and its affiliates. Copies of these filings may be obtained by accessing the SEC website at sec.gov.

30	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

Columbia Diversified Fixed Income Allocation ETF

Buying and Selling Fund Shares (continued)

Buying Fund Shares Directly from the Fund

Fund shares can only be purchased directly from the Fund by an Authorized Participant or through an Authorized Participant. An “Authorized Participant” is a participant of the Continuous Net Settlement System of the NSCC or the DTC that has executed a Participant Agreement with the Distributor, and accepted by the Transfer Agent. The Distributor will provide a list of Authorized Participants upon request. Authorized Participants may purchase Creation Units of shares, and sell individual shares on the Exchange. See Continuous Offering below.

An Authorized Participant can purchase Fund shares directly from the Fund only in Creation Units or multiples thereof. The number of shares in a Creation Unit may, but is not expected to, change over time. The Fund will not issue fractional Creation Units. Creation Units may be purchased in exchange for a basket of securities or other portfolio instruments (known as the In-Kind Creation Basket and a Cash Component ) or for an all cash payment (the Cash Value ). The Fund reserves the right to reject any purchase request at any time, for any reason, and without notice.

In-Kind Creation Basket. On each business day, prior to the opening of trading on the Exchange, BNY Mellon will post on the NSCC bulletin board the In-Kind Creation Basket for the Fund for that day. The In-Kind Creation Basket will identify the name and number of shares of each security or other instrument that must be contributed to the Fund for each Creation Unit purchased. The Fund reserves the right to accept a nonconforming or “custom” In-Kind Creation Basket under certain limited circumstances. In the case of custom orders, the order must be received by the Distributor no later than 3:00 p.m. ET.

Balancing Amount and Cash Component. In addition to the In-Kind Creation Basket, a purchaser will either pay to, or receive from, the Fund an amount of cash (“Balancing Amount”) equal to the difference between the NAV of a Creation Unit and the value of the securities in the In-Kind Creation Basket. The Balancing Amount ensures that the consideration paid by an investor for a Creation Unit is exactly equal to the value of the Creation Unit. BNY Mellon will publish, on a daily basis, information about the previous business day’s Balancing Amount. To the extent a purchaser is not owed a Balancing Amount larger than the Creation Transaction Fee, described below, the purchaser also must pay a Creation Transaction Fee, in cash. The Balancing Amount and the Creation Transaction Fee, taken together, are referred to as the Cash Component.

Cash Value. In lieu of depositing the In-Kind Creation Basket and Balancing Amount, a Fund Deposit may consist solely of cash in an amount equal to the NAV of a Creation Unit, which amount is referred to as the Cash Value. Any such purchases will be subject to a variable charge, as explained below. BNY Mellon will publish, on a daily basis, information about the Cash Value of a Creation Unit. With respect to any Fund Deposit of a Cash Value, the Cash Value and Creation Transaction Fee, taken together, are referred to as the Cash Component.

Placement of Purchase Orders. All purchase orders must be placed by or through an Authorized Participant. Purchase orders will be processed either through a manual clearing process run by DTC or through an enhanced clearing process that is available only to those DTC participants that also are participants in the Continuous Net Settlement System of the NSCC. Authorized Participants that do not use the NSCC’s enhanced clearing process may be charged a higher Creation Transaction Fee (discussed below). A purchase order must be received by the Distributor prior to the end of the business day (generally 4:00 p.m., Eastern time) and Fund Deposits of Cash Values generally must be received two hours prior (with respect to each, the “Order Cut-Off Time”) on the day the order is placed, and all other procedures set forth in the Participant Agreement must be followed, in order to receive the NAV determined on that day. On days when the NYSE or the bond markets close earlier than normal (for example, the day before a holiday), the Fund may require purchase orders to be placed earlier in the day.

Transaction Fee on Purchases of Creation Units. The Fund may impose a “Creation Transaction Fee” on purchases of Creation Units. The Creation Transaction Fee is paid to the Fund. The fee is designed to protect existing shareholders of the Fund from the costs associated with issuing Creation Units.

The Creation Transaction Fee applied to purchases of Creation Units of the Fund includes two components — a standard fee and a variable charge, as described in the table below. The variable charge does not apply to creation transactions involving only an In-Kind Creation Basket. A higher Creation Transaction Fee up to the Maximum Transaction Fee noted in the table below may be imposed on purchases outside the NSCC’s enhanced clearing

32	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

Buying and Selling Fund Shares (continued)

process, including purchases involving nonconforming In-Kind Creation Baskets or cash. Investors who, directly or indirectly, use the services of a broker or other such intermediary to compile the securities or other instruments in the In-Kind Creation Basket may pay additional fees for these services.

    

	Transaction Fees
	Standard Transaction Fee	Maximum Transaction Fee	Variable Charge
	$500*	$2,000*	Up to 2.0%

*	The Creation Transaction Fee may be as high as the Maximum Transaction Fee for transactions outside the NSCC's enhanced clearing process.

Redeeming Fund Shares Directly from the Fund

Fund shares can only be redeemed directly with the Fund by an Authorized Participant or through an Authorized Participant. An Authorized Participant may redeem Fund shares directly from the Fund only in Creation Units or multiples thereof. Creation Units may be redeemed in exchange for a “Fund Redemption.” A Fund Redemption consists of (i) a basket of securities — known as the In-Kind Redemption Basket — and Balancing Amount, or (ii) a Cash Value, in all instances equal to the value of a Creation Unit.

In-Kind Redemption Basket. If different from the In-Kind Creation Basket, the composition of the In-Kind Redemption Basket will be available on the NSCC bulletin board; otherwise, the In-Kind Creation Basket posted may be assumed to be the In-Kind Redemption Basket. The Fund may honor a redemption request with a nonconforming or “custom” In-Kind Redemption Basket under certain limited circumstances.

Balancing Amount and Cash Component. In addition to the In-Kind Redemption Basket, a redeeming investor will receive from, or pay to, the Fund a Balancing Amount in cash, depending on whether the NAV of a Creation Unit is higher or lower than the value of the securities in the In-Kind Redemption Basket. If due to receive a Balancing Amount, the amount actually received will be reduced by the amount of the applicable Redemption Transaction Fee, described below. The Balancing Amount and the Redemption Transaction Fee, taken together, are referred to as the Cash Component.

Cash Value. In lieu of the In-Kind Redemption Basket and a Balancing Amount, Creation Units may be redeemed for a Fund Redemption consisting solely of cash in an amount equal to the NAV of a Creation Unit, which amount is referred to as the Cash Value. Such redemptions will be subject to a variable charge, as explained above. The transfer agent will publish, on a daily basis, information about the Cash Value of a Creation Unit. With respect to any Fund Redemption consisting of a Cash Value, the Cash Value and Redemption Transaction Fee, taken together, are referred to as the Cash Component.

Placement of Redemption Orders. As with purchases, redemptions must be processed either through the DTC process or the enhanced NSCC process. A redemption order is deemed received on the date of transmittal if it is received by the Distributor unless the NYSE or the bond markets close early that day in which case the Fund may require redemption orders to be received earlier in the day, and if all other procedures set forth in the Participant Agreement are followed.

Transaction Fee on Redemptions of Creation Units. The Fund may impose a Redemption Transaction Fee on redemption of Creation Units. The amount of the Redemption Transaction Fee on redemptions effected through the NSCC and DTC is the same as that applied to creations and a variable charge may apply to the Cash Value. (See "Transaction Fee on Purchases of Creation Units"). The Redemption Transaction fee is paid to the Fund. The fee is designed to protect existing shareholders of the Fund from the costs associated with redeeming Creation Units.

Additional Information About Buying and Selling Fund Shares

Legal Restrictions on Transactions in Certain Securities. An investor subject to a legal restriction with respect to a particular security required to be deposited in connection with the purchase of a Creation Unit may, at the Fund’s discretion, be permitted to deposit an equivalent amount of cash in substitution for any security which would otherwise be included in the In-Kind Creation Basket applicable to the purchase of a Creation Unit.

Prospectus 2019

33

Columbia Diversified Fixed Income Allocation ETF

Buying and Selling Fund Shares (continued)

Creations and redemptions of shares will be subject to applicable federal and state securities laws, including that securities accepted for deposit and securities used to satisfy redemption requests are sold in transactions that would be exempt from registration under the Securities Act of 1933, as amended (the Securities Act). The Fund (whether or not it otherwise permits cash redemptions) reserves the right to redeem Creation Units for cash to the extent that an investor could not lawfully purchase or the Fund could not lawfully deliver specific securities under such laws or the local laws of a jurisdiction in which the Fund invests. An Authorized Participant or an investor for which it is acting subject to a legal restriction with respect to a particular security included in an In-Kind Redemption Basket may be paid an equivalent amount of cash. An Authorized Participant or redeeming investor for which it is acting that is not a qualified institutional buyer (QIB) as defined in Rule 144A under the Securities Act will not be able to receive, as part of a redemption, restricted securities eligible for resale under Rule 144A.

Continuous Offering. Authorized Participants should be aware of certain legal risks unique to investors purchasing Creation Units directly from the Fund. Because shares may be issued on an ongoing basis, a “distribution” of shares could be occurring at any time. Certain activities that Authorized Participants perform with respect to the sale of shares could, depending on the circumstances, result in Authorized Participants being deemed to be a participant in the distribution, in a manner that could render Authorized Participants a statutory underwriter and subject Authorized Participants to the prospectus delivery and liability provisions of the Securities Act. For example, Authorized Participants could be deemed a statutory underwriter if Authorized Participants purchase Creation Units from the issuing Fund, break them down into the constituent shares, and sell those shares directly to customers, or if Authorized Participants choose to couple the creation of a supply of new shares with an active selling effort involving solicitation of secondary market demand for shares. Whether a person is an underwriter for purposes of the Securities Act depends upon all of the facts and circumstances pertaining to that person’s activities, and the examples mentioned here should not be considered a complete description of all the activities that could cause Authorized Participants to be deemed an underwriter.

Broker-dealer firms should also note that dealers who are not “underwriters” but are effecting transactions in shares, whether or not participating in the distribution of shares, are generally required to deliver a prospectus. This is because the prospectus delivery exemption in Section 4(3) of the Securities Act is not available in respect of such transactions as a result of Section 24(d) of the 1940 Act. As a result, broker-dealer firms should note that dealers who are not “underwriters” but are participating in a distribution (as opposed to engaging in ordinary secondary market transactions), and thus dealing with shares as part of an unsold allotment within the meaning of Section 4(3)(C) of the Securities Act, will be unable to take advantage of the prospectus delivery exemption provided by Section 4(3) of the Securities Act. For delivery of prospectuses to exchange members, the prospectus delivery mechanism of Rule 153 under the Securities Act is only available with respect to transactions on a national exchange.

Active Investors and Market Timing

The Board has determined not to adopt policies and procedures designed to prevent or monitor for frequent purchases and redemptions of the Fund’s shares because investors primarily transact in Fund shares on the secondary market. Frequent trading of shares on the secondary market does not disrupt portfolio management, increase the Fund’s trading costs, lead to realization of capital gains or otherwise harm Fund shareholders because these trades do not involve the issuance or redemption of Fund shares.

The Fund sells and redeems its shares at NAV only in Creation Units pursuant to the terms of a Participant Agreement between an Authorized Participant and the Distributor. With respect to such trades directly with the Fund to the extent effected in-kind (i.e., for securities), they generally would not cause the harmful effects that may result from frequent cash trades.

The Board recognizes that to the extent that the Fund allows or requires trades to be effected in whole or in part in cash, those trades could result in dilution to a Fund and increased transaction costs, which could negatively impact the Fund’s ability to achieve its investment objective. The Board also recognizes, however, that direct trading by Authorized Participants is critical to ensuring that the Fund’s shares trade at or close to NAV. Further, the Fund may

34	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

Buying and Selling Fund Shares (continued)

employ fair valuation pricing to minimize the potential for dilution from market timing. Moreover, the Fund imposes transaction fees on purchases and redemptions of Fund shares reflecting the fact that the Fund’s costs increase in those circumstances. The Fund reserves the right to impose additional restrictions on disruptive, excessive or short-term purchases.

Distribution and Service Fees

The Board has approved, and the Fund has adopted, a distribution and service plan (the Plan) pursuant to Rule 12b-1 under the 1940 Act. Under the Plan, the Fund is authorized to pay distribution fees to the Distributor and other firms that provide distribution and shareholder services (Service Providers). If a Service Provider provides such services, the Fund may pay fees at an annual rate not to exceed 0.25% of average daily net assets, pursuant to Rule 12b-1 under the 1940 Act.

No distribution or service fees are currently paid by the Fund, however, and there are no current plans to impose these fees. Future payments may be made under the Plan without any further shareholder approval. In the event Rule 12b-1 fees are charged, over time they would increase the cost of an investment in the Fund.

Intraday Indicative Value (IIV)

The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the Business Day (as defined below), (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close (except such quotations may be updated to reflect currency fluctuations), which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Determination of Net Asset Value

Prospectus 2019

35

Columbia Diversified Fixed Income Allocation ETF

Buying and Selling Fund Shares (continued)

Equity securities are valued primarily on the basis of market quotations reported on stock exchanges and other securities markets around the world. If an equity security is listed on a national exchange, the security is valued at the closing price or, if the closing price is not readily available, the mean of the closing bid and asked prices. Certain equity securities, debt securities and other assets are valued differently. For instance, bank loans trading in the secondary market are valued primarily on the basis of indicative bids, fixed income investments maturing in 60 days or less are valued primarily using the amortized cost method, unless this methodology results in a valuation that does not approximate the market value of these securities, and those maturing in excess of 60 days are valued primarily using a market-based price obtained from a pricing service, if available. Investments in other open-end funds are valued at their published NAVs. Both market quotations and indicative bids are obtained from outside pricing services approved and monitored pursuant to a policy approved by the Fund's Board.

If a market price is not readily available or is deemed not to reflect market value, the Fund will determine the price of a portfolio security based on a determination of the security's fair value pursuant to a policy approved by the Fund's Board. In addition, the Fund may use fair valuation to price securities that trade on a foreign exchange when a significant event has occurred after the foreign exchange closes but before the time at which the Fund's share price is calculated. Foreign exchanges typically close before the time at which Fund share prices are calculated, and may be closed altogether on some days when the Fund is open. Such significant events affecting a foreign security may include, but are not limited to: (1) corporate actions, earnings announcements, litigation or other events impacting a single issuer; (2) governmental action that affects securities in one sector or country; (3) natural disasters or armed conflicts affecting a country or region; or (4) significant domestic or foreign market fluctuations. The Fund uses various criteria in determining whether a foreign security's market price is readily available and reflective of market value and, if not, the fair value of the security. To the extent the Fund has significant holdings of small cap stocks, high-yield bonds, floating rate loans, or tax-exempt, foreign or other securities that may trade infrequently, fair valuation may be used more frequently than for other funds.

Fair valuation may have the effect of reducing stale pricing arbitrage opportunities presented by the pricing of Fund shares. However, when the Fund uses fair valuation to price securities, it may value those securities higher or lower than another fund would have priced the security. Also, the use of fair valuation may cause the Fund's performance to diverge to a greater degree from the performance of various benchmarks used to compare the Fund's performance because benchmarks generally do not use fair valuation techniques. Because of the judgment involved in fair valuation decisions, there can be no assurance that the value ascribed to a particular security is accurate.

36	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

Columbia Diversified Fixed Income Allocation ETF

Distributions and Taxes (continued)

Taxes

You should be aware of the following considerations applicable to the Fund:

■

The Fund intends to qualify and to be eligible for treatment each year as a regulated investment company. A regulated investment company generally is not subject to tax at the fund level on income and gains from investments that are distributed to shareholders. However, the Fund's failure to qualify for treatment as a regulated investment company would result in Fund-level taxation, and consequently, a reduction in income available for distribution to you and in the NAV of your shares. Even if the Fund qualifies for treatment as a regulated investment company, the Fund may be subject to federal excise tax on certain undistributed income or gains.

■

Otherwise taxable distributions generally are taxable to you when paid, whether they are paid in cash or automatically reinvested in additional Fund shares. Dividends paid in January are deemed paid on December 31 of the prior year if the dividend was declared and payable to shareholders of record in October, November, or December of such prior year.

■

Distributions of the Fund's ordinary income and net short-term capital gain, if any, generally are taxable to you as ordinary income. Distributions of the Fund's net long-term capital gain, if any, generally are taxable to you as long-term capital gain. Whether capital gains are long-term or short-term is determined by how long the Fund has owned the investments that generated them, rather than how long you have owned your shares.

■

From time to time, a distribution from the Fund could constitute a return of capital. A return of capital is a return of an amount of your original investment and is not a distribution of income or capital gain from the Fund. Therefore, a return of capital is not taxable to you so long as the amount of the distribution does not exceed your tax basis in your Fund shares. A return of capital reduces your tax basis in your Fund shares, with any amounts exceeding such basis generally taxable as capital gain.

■

If you are an individual and you meet certain holding period and other requirements for your Fund shares, a portion of your distributions may be treated as “qualified dividend income” taxable at the lower net long-term capital gain rates instead of the higher ordinary income rates. Qualified dividend income is income attributable to the Fund's dividends received from certain U.S. and foreign corporations, as long as the Fund meets certain holding period and other requirements for the stock producing such dividends.

■	Certain high-income individuals (as well as estates and trusts) are subject to a 3.8% tax on net investment income. For individuals, the 3.8% tax applies to the lesser of (1) the amount (if any) by which the taxpayer's modified adjusted gross income exceeds certain threshold amounts or (2) the taxpayer's “net investment income.”
	Net investment income generally includes for this purpose dividends, including any capital gain dividends, paid by the Fund, and net gains recognized on the sale, redemption or exchange of shares of the Fund.

■

Certain derivative instruments when held in the Fund's portfolio subject the Fund to special tax rules, the effect of which may be to, among other things, accelerate income to the Fund, defer Fund losses, cause adjustments in the holding periods of Fund portfolio securities, or convert capital gains into ordinary income, short-term capital losses into long-term capital losses or long-term capital gains into short-term capital gains. These rules could therefore affect the amount, timing and/or character of distributions to shareholders.

■

Generally, a Fund realizes a capital gain or loss on an option when the option expires, or when it is exercised, sold or otherwise terminated. However, if an option is a “section 1256 contract,” which includes most traded options on a broad-based index, and the Fund holds such option at the end of its taxable year, the Fund is deemed to sell such option at fair market value at such time and recognize any gain or loss thereon, which is generally deemed to be 60% long-term and 40% short-term capital gain or loss, as described further in the SAI.

■

Income and proceeds received by the Fund from sources within foreign countries may be subject to foreign taxes. If at the end of the taxable year more than 50% of the value of the Fund's assets consists of securities of foreign corporations, and the Fund makes a special election, you will generally be required to include in your income for U.S. federal income tax purposes your share of the qualifying foreign income taxes paid by the Fund in respect of

38	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

Distributions and Taxes (continued)

its foreign portfolio securities. You may be able to claim a foreign tax credit or deduction in respect of this amount, subject to certain limitations. There is no assurance that the Fund will make this election for a taxable year, even if it is eligible to do so.

■

A sale, redemption or exchange of Fund shares is a taxable event. This includes redemptions where you are paid in securities. Your sales, redemptions and exchanges of Fund shares, including those paid in securities or other instruments, usually will result in a taxable capital gain or loss to you, equal to the difference between the amount you receive for your shares (or are deemed to have received in the case of exchanges) and your adjusted tax basis in the shares, which is generally the amount you paid (or are deemed to have paid in the case of exchanges) for them. Any such capital gain or loss generally will be long-term capital gain or loss if you have held your Fund shares for more than one year at the time of sale or exchange. In certain circumstances, capital losses may be converted from short-term to long-term; in other circumstances, capital losses may be disallowed under the “wash sale” rules.

■

Your broker will be responsible for furnishing tax reporting information for Fund shares held in a nonqualified account, shareholder reports, and other communications from the Fund. For sales or exchanges of Fund shares acquired in a nonqualified account after 2011, your broker is required to report basis and holding period information to you and the IRS. Your broker may offer a choice of basis calculation methods. Contact your broker to determine which basis methods are available for your account.

■

The Fund or, in the case of sales of Fund shares in the secondary market, your broker, will generally be required by federal law to withhold tax on any distributions and proceeds paid to you if you have not provided a correct TIN or have not certified to the Fund or its agent, or your broker, as the case may be, that withholding does not apply.

■

For Authorized Participants Purchasing and Redeeming in Creation Units: An Authorized Participant that exchanges equity securities for one or more Creation Units will generally recognize a gain or a loss on the exchange. The gain or loss will be equal to the difference between (i) the market value of the Creation Unit(s) at the time and, (ii) the exchanger’s aggregate basis in the securities surrendered plus (or minus) the Cash Component paid (or received). A person who redeems one or more Creation Units for equity securities will generally recognize a gain or loss equal to the difference between (i) the exchanger’s basis in the Creation Unit(s) and, (ii) the aggregate market value of the securities received plus (or minus) the Cash Component received (or paid). The IRS, however, may assert that a loss realized upon an exchange of securities for Creation Unit(s) cannot be deducted currently under the rules governing “wash sales,” or on the basis that there has been no significant change in economic position. Persons exchanging securities should consult their own tax advisors with respect to whether wash sale rules apply and when a loss might be deductible. Any capital gain or loss realized upon a redemption of one or more Creation Units is generally treated as long-term capital gain or loss if the Creation Unit(s) have been held for more than one year and as short-term capital gain or loss if they have been held for one year or less. If you purchase or redeem Creation Units, you will be sent a confirmation statement showing how many shares you purchased or sold and at what price.

Prospectus 2019

39

Columbia Diversified Fixed Income Allocation ETF

Premium/Discount Information

Information regarding how often the shares of the Fund traded on the Exchange at a price above (at a premium) or below (at a discount) the NAV of the Fund can be found at columbiathreadneedleetf.com/dial.

40	Prospectus 2019

Columbia Diversified Fixed Income Allocation ETF

[This page intentionally left blank]

[This page intentionally left blank]

Columbia Diversified
Fixed Income Allocation ETF

225 Franklin Street
Boston, MA 02110

Beta Advantage ^® ETFs

Columbia Multi-Sector Municipal Income ETF

    

Ticker Symbol

MUST

This prospectus provides important information about Columbia Multi-Sector Municipal Income ETF (the Fund), a passively managed exchange-traded fund (the ETF) and series of Columbia ETF Trust I (the Trust), that you should know before investing. Please read it carefully and keep it for future reference.

These securities have not been approved or disapproved by the Securities and Exchange Commission (SEC) nor has the SEC passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Shares of the Fund are listed and traded on NYSE Arca, Inc. (the Exchange).

No person has been authorized to give any information or to make any representations other than those contained in this prospectus and the Fund's Statement of Additional Information (SAI) dated March 1, 2019 (which is incorporated by reference into this prospectus and is legally a part of this prospectus) and, if given or made, such information or representations may not be relied upon as having been authorized by us.

Columbia Multi-Sector Municipal Income ETF

Summary of the Fund

Columbia Multi-Sector Municipal Income ETF

Summary of the Fund (continued)

Columbia Multi-Sector Municipal Income ETF

Summary of the Fund (continued)

Beta Advantage ^® Strategy to Investing in the Municipal High Quality Revenue Sector. As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the: (i) Bloomberg Barclays Municipal Bond: Housing Index that meet the following criteria: are rated Aa2 or higher; have a remaining maturity of between and including 2 and 15 years; have an outstanding par value of at least $10 million; and were issued as part of a transaction of at least $100 million; and (ii) the Bloomberg Barclays Municipal Bond: Water & Sewer Index that meet the following criteria: are rated A2 or higher; have a remaining maturity of between and including 2 and 10 years; have an outstanding par value of at least $15 million; and were issued as part of a transaction of at least $100 million. At January 31, 2019, this sector held 764 securities.

Beta Advantage ^® Strategy to Investing in the Municipal Core GO Sector. As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the Bloomberg Barclays Municipal Bond: GO Index that meet the following criteria: are rated Aa3 or higher; have a remaining maturity of between and including 2 and 10 years; have an outstanding par value of at least $15 million for local GO bonds and $25 million for state GO bonds; and were issued as part of a transaction of at least $100 million. At January 31, 2019, this sector held 1,704 securities.

Beta Advantage ^® Strategy to Investing in the Municipal High Yield Sector. As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the Bloomberg Barclays Municipal High Yield Bond Index that meet the following criteria: are rated B3 or higher; have a remaining maturity of between and including 10 and 25 years; have an outstanding par value of at least $5 million; and were issued as part of a transaction of at least $25 million. Tobacco bonds are excluded from this sector. At January 31, 2019, this sector held 424 securities.

All credit rating designations noted above are according to Bloomberg Barclays’ index rating methodology.

The Fund may invest, as part of its 80% investment policy or otherwise when the Investment Manager believes it will help the Fund track the Index, in privately placed and other securities or instruments that are purchased and sold pursuant to Rule 144A or other exemptions under the Securities Act of 1933, as amended (the 1933 Act), subject to liquidity determinations and certain regulatory restrictions.

The Index is reconstituted and rebalanced monthly on the last business day of each month.

Columbia Management expects to utilize a “representative sampling” strategy whereby the Fund invests in only some of the component securities of the Index that, collectively, are believed by the Investment Manager to generally reflect the same risk and return characteristics of the Index. As such, the Fund may not track the Index with the same degree of accuracy as would an investment vehicle replicating (or investing in) the entire Index. Through its representative sampling investment technique, the Fund expects to typically hold approximately 120 bonds, which is a small subset of the total number of holdings in the Index, which, as of January 31, 2019, had 5,816 holdings. As Fund assets under management increase, the Fund’s holdings will likely increase. There may be instances in which the Fund may overweight (or underweight) an Index holding, purchase (or sell) instruments not in the Index as a substitute for one or more securities in the Index or utilize various combinations of other available investment techniques in seeking to replicate the performance of the Index. Under certain circumstances or conditions or due to other factors, including, for example, the size of the Fund (in terms of assets under management), the Fund may increase its number of holdings beyond the typical number of holdings stated above.

The Fund may sell securities or other holdings that are represented in the Index or purchase securities or make other investments that are not yet represented in the Index in anticipation of their removal from or addition to the Index by the Index Provider.

The Investment Manager does not invest the Fund’s assets based on its view of the investment merits of a particular security or company, neither does it conduct fundamental investment research or analysis, nor seek to forecast or otherwise consider market movements, conditions or trends in managing the Fund’s assets. The Fund pursues its investment objective of correlating performance with the Index regardless of market conditions and does not take defensive positions.

To the extent the Index is concentrated in a particular sector or industry, the Fund will necessarily be concentrated in that sector or industry.

Prospectus 2019

5

Columbia Multi-Sector Municipal Income ETF

Summary of the Fund (continued)

Columbia Multi-Sector Municipal Income ETF

Summary of the Fund (continued)

higher-rated instruments. Non-investment grade debt instruments may be subject to greater price fluctuations and are more likely to experience a default than investment grade debt instruments and therefore may expose the Fund to increased credit risk.

Early Close/Late Close/Trading Halt Risk.  An exchange or market may close early, close late or issue trading halts on specific securities, or the ability to buy or sell certain securities may be restricted, which may result in the Fund being unable to buy or sell these securities. In these circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments, may incur substantial trading losses and/or may be prevented from sufficiently tracking the performance of the Index.

Fund Shares Liquidity Risk. Although the Fund’s shares are listed on the Exchange, there can be no assurance that an active, liquid or otherwise orderly trading market for shares will be established or maintained by market makers or Authorized Participants, particularly in times of stressed market conditions. In this regard, there is no obligation for market makers to make a market in the Fund’s shares or for Authorized Participants to submit purchase or redemption orders for creation units. Accordingly, if such parties determine not to perform their respective roles, this could, in turn, lead to variances between the market price of the Fund’s shares and the underlying value of those shares. Trading in Fund shares on the Exchange also may be disrupted or even halted due to market conditions or for reasons that, in the view of the Exchange, make trading in Fund shares inadvisable. In addition, trading in Fund shares on the Exchange may be subject to trading halts caused by extraordinary market volatility pursuant to the Exchange “circuit breaker” rules. There also can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund’s shares will continue to be met or will remain unchanged.

High-Yield Investments Risk. Securities and other debt instruments held by the Fund that are rated below investment grade (commonly called “high-yield” or “junk” bonds) and unrated debt instruments of comparable quality expose the Fund to a greater risk of loss of principal and income than a fund that invests solely or primarily in investment grade debt instruments. In addition, these investments have greater price fluctuations, are less liquid and are more likely to experience a default than higher-rated debt instruments. High-yield debt instruments are considered to be predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal.

Index Methodology Risk. The Fund seeks performance that corresponds to the performance of the Index. There is no guarantee or assurance that the Index will achieve high, or even positive, returns. The Index may underperform more traditional indices. The Fund could lose value while other indices or measures of market performance increase in value or performance. In addition, the Fund may be subject to the risk that the index provider may not follow its stated methodology for construction of the Index and/or achieve the index provider’s intended performance objective. Errors may result in a negative performance impact to the Fund and its shareholders.

Interest Rate Risk. Interest rate risk is the risk of losses attributable to changes in interest rates. In general, if prevailing interest rates rise, the values of debt instruments tend to fall, and if interest rates fall, the values of debt instruments tend to rise. Changes in the value of a debt instrument usually will not affect the amount of income the Fund receives from it but will generally affect the value of your investment in the Fund. Changes in interest rates may also affect the liquidity of the Fund’s investments in debt instruments. In general, the longer the maturity or duration of a debt instrument, the greater its sensitivity to changes in interest rates. Interest rate declines also may increase prepayments of debt obligations, which, in turn, would increase prepayment risk. Similarly, a period of rising interest rates may negatively impact the Fund’s performance. Actions by governments and central banking authorities can result in increases in interest rates. Such actions may negatively affect the value of debt instruments held by the Fund, resulting in a negative impact on the Fund's performance and NAV. Any interest rate increases could cause the value of the Fund’s investments in debt instruments to decrease. Rising interest rates may prompt redemptions from the Fund, which may force the Fund to sell investments at a time when it is not advantageous to do so, which could result in losses.

Limitations of Intraday Indicative Value (IIV) Risk. The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the business day, (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the

Prospectus 2019

7

Columbia Multi-Sector Municipal Income ETF

Summary of the Fund (continued)

calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close, which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. For example, if the Fund fair values portfolio securities, the Fund’s NAV may deviate from the approximate per share value of the Fund’s published basket of portfolio securities (i.e., the IIV), which could result in the market prices for Fund shares deviating from NAV. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Decreases in the number of financial institutions, including banks and broker-dealers, willing to make markets (match up sellers and buyers) in the Fund’s investments or decreases in their capacity or willingness to trade such investments may increase the Fund’s exposure to this risk. The debt market has experienced considerable growth, and financial institutions making markets in instruments purchased and sold by the Fund (e.g., bond dealers) have been subject to increased regulation. The impact of that growth and regulation on the ability and willingness of financial institutions to engage in trading or “making a market” in such instruments remains unsettled. Certain types of investments, such as lower-rated securities or those that are purchased and sold in over-the-counter markets, may be especially subject to liquidity risk. Securities or other assets in which the Fund invests may be traded in the over-the-counter market rather than on an exchange and therefore may be more difficult to purchase or sell at a fair price, which may have a negative impact on the Fund’s performance. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions of creation units, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market. In certain circumstances, the Fund might not be able to dispose of certain holdings quickly or at fair prices, preventing the Fund from tracking the Index. The municipal securities market is an over-the-counter market, which means that the Fund purchases and sells investments through municipal bond dealers. The Fund’s ability to sell investments held in its portfolio is dependent on the willingness and ability of market participants to provide bids that, in the view of portfolio management, reflect current market prices. Adverse market conditions could result in a lack of liquidity by reducing the number of ready buyers. In addition, in stressed market conditions, the market for Fund shares may become less liquid. Deterioration in the liquidity of Fund shares may adversely impact the liquidity of the Fund's underlying portfolio securities. These adverse impacts on the liquidity of Fund shares and on the liquidity of the Fund's underlying portfolio securities could in turn lead to differences between the market price of Fund shares and the underlying value of those shares.

Market Price Relative to NAV Risk. Shares of the Fund may trade at prices that vary from Fund NAV. Shares of the Fund are listed for trading on the Exchange and are bought and sold in the secondary market at market prices that may differ, in some cases significantly, from their NAV. The NAV of the Fund will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of shares, however, will generally fluctuate in response to changes in NAV, as well as the relative supply of, and demand for, Fund shares on the Exchange. The Investment

8	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

Summary of the Fund (continued)

Manager cannot predict whether Fund shares will trade below, at or above their NAV. Price differences may result because of, among other factors, supply and demand forces in the secondary trading market for Fund shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings. In this connection, if a shareholder purchases Fund shares at a time when the market price is at a premium to the NAV or sells shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses. Different investment strategies or techniques, including those intended to be defensive in nature, including, as examples, stop loss orders to sell an ETF’s shares in the secondary market during negative market events or conditions, such as a “flash crash” or other market disruptions may not work as intended and may produce significant losses to investors. Investors should consult their financial intermediary prior to using any such investment strategies or techniques, or before investing in the Fund.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. An investment in the Fund could lose money over short or long periods.

Money Market Fund Investment Risk. An investment in a money market fund is not a bank deposit and is not insured or guaranteed by any bank, the FDIC or any other government agency. Certain money market funds float their NAV while others seek to preserve the value of investments at a stable NAV (typically, $1.00 per share). An investment in a money market fund, even an investment in a fund seeking to maintain a stable NAV per share, is not guaranteed and it is possible for the Fund to lose money by investing in these and other types of money market funds. If the liquidity of a money market fund’s portfolio deteriorates below certain levels, the money market fund may suspend redemptions (i.e., impose a redemption gate) and thereby prevent the Fund from selling its investment in the money market fund or impose a fee of up to 2% on amounts the Fund redeems from the money market fund (i.e., impose a liquidity fee). These measures may result in an investment loss or prohibit the Fund from redeeming shares when the Investment Manager would otherwise redeem shares. In addition to the fees and expenses that the Fund directly bears, the Fund indirectly bears the fees and expenses of any money market funds in which it invests, including affiliated money market funds. By investing in a money market fund, the Fund will be exposed to the investment risks of the money market fund in direct proportion to such investment. To the extent the Fund invests in instruments such as derivatives, the Fund may hold investments, which may be significant, in money market fund shares to cover its obligations resulting from the Fund’s investments in derivatives. Money market funds and the securities they invest in are subject to comprehensive regulations. The enactment of new legislation or regulations, as well as changes in interpretation and enforcement of current laws, may affect the manner of operation, performance and/or yield of money market funds.

Municipal Securities Risk. Municipal securities are debt obligations generally issued to obtain funds for various public purposes, including general financing for state and local governments, or financing for a specific project or public facility, and include obligations of the governments of the U.S. territories, commonwealths and possessions such as Guam, Puerto Rico and the U.S. Virgin Islands to the extent such obligations are exempt from state and U.S. federal income taxes. The value of municipal securities can be significantly affected by actual or expected political and legislative changes at the federal or state level. Municipal securities may be fully or partially backed by the taxing authority of the local government, by the credit of a private issuer, by the current or anticipated revenues from a specific project or specific assets or by domestic or foreign entities providing credit support, such as letters of credit, guarantees or insurance, and are generally classified into general obligation bonds and special revenue obligations. Because many municipal securities are issued to finance projects in sectors such as education, health care, transportation and utilities, conditions in those sectors can affect the overall municipal market.

Issuers in a state, territory, commonwealth or possession in which the Fund invests may experience significant financial difficulties for various reasons, including as the result of events that cannot be reasonably anticipated or controlled such as social conflict or unrest, labor disruption and natural disasters. Such financial difficulties may lead to credit rating downgrades of such issuers which in turn, could affect the market values and marketability of many or all municipal obligations of issuers in such state, territory, commonwealth or possession. The value of the Fund’s shares will be negatively impacted to the extent it invests in such securities. The Fund’s annual and semiannual reports show the Fund’s investment exposures at a point in time. The risk of investing in the Fund is directly correlated to the Fund’s investment exposures.

Prospectus 2019

9

Columbia Multi-Sector Municipal Income ETF

Summary of the Fund (continued)

Securities issued by a particular state and its instrumentalities are subject to the risk of unfavorable developments in such state. A municipal security can be significantly affected by adverse tax, legislative, regulatory, demographic or political changes as well as changes in a particular state's (state and its instrumentalities) financial, economic or other condition and prospects.

The Fund’s investments in municipal securities may include securities of issuers in the electric, transportation, education, and leasing sectors (collectively, these sectors compose the Municipal Core Revenue Sector), which subjects the Fund’s investments to the risks associated with those sectors, including the risk of regulatory action or policy changes by numerous governmental agencies and bodies, including federal, state, and local governmental agencies, as well as requirements imposed by private entities. Issuers in the Municipal Core Revenue Sector are subject to certain risks, including competitive pricing pressures, the rising cost of products and services (especially for companies dependent upon a relatively limited number of products or services), government regulation, obtaining and protecting patents (or the failure to do so), product liability and other similar litigation, labor disputes, lease supply and demand, and technology obsolescence, amongst other factors and conditions.

The Fund’s investments in municipal securities may include securities of issuers in the health care sector, which subjects the Fund’s investments to the risks associated with that sector, including the risk of regulatory action or policy changes by numerous governmental agencies and bodies, including federal, state, and local governmental agencies, as well as requirements imposed by private entities, such as insurance companies. A major source of revenue for the health care industry is payments from the Medicare and Medicaid programs. As a result, the industry is sensitive to legislative changes and reductions in governmental spending for such programs. Numerous other factors may affect the industry, such as general and local economic conditions, demand for services, expenses (including, among others, malpractice insurance premiums) and competition among health care providers. Additional factors also may adversely affect health care facility operations, such as adoption of legislation proposing a national health insurance program, other state or local health care reform measures, medical and technological advances that alter the need for or cost of health services or the way in which such services are delivered, changes in medical coverage that alter the traditional fee-for-service revenue stream, and efforts by employers, insurers, and governmental agencies to reduce the costs of health insurance and health care services.

New Fund Risk. The Fund is a newly-formed ETF. Accordingly, investors in the Fund bear the risk that the Fund may not be successful in implementing its investment strategy of replicating the Index, which could result in the Fund being liquidated at any time without shareholder approval and/or at a time that may not be favorable for shareholders. Such a liquidation could have negative tax consequences for shareholders.

Passive Investment Risk. The Fund is not “actively” managed and may be affected by a general decline in market segments related to its underlying index. The Fund invests in securities or instruments included in, or believed by the Investment Manager to be representative of, its underlying index, regardless of their investment merits. The Fund does not seek temporary defensive positions when markets decline or appear overvalued. The decision of whether to remove a security from an index is made by an independent index provider who is not affiliated with the Fund or the Investment Manager.

Prepayment and Extension Risk. Prepayment and extension risk is the risk that a bond or other security or investment might, in the case of prepayment risk, be called or otherwise converted, prepaid or redeemed before maturity and, in the case of extension risk, that the investment might not be called as expected. In the case of prepayment risk, if the investment is converted, prepaid or redeemed before maturity, the portfolio managers may not be able to invest the proceeds in other investments providing as high a level of income, resulting in a reduced yield to the Fund. In the case of mortgage- or other asset-backed securities, as interest rates decrease or spreads narrow, the likelihood of prepayment increases. Conversely, extension risk is the risk that an unexpected rise in interest rates will extend the life of a mortgage- or other asset-backed security beyond the prepayment time. If the Fund’s investments are locked in at a lower interest rate for a longer period of time, the portfolio managers may be unable to capitalize on securities with higher interest rates or wider spreads.

Reinvestment Risk. Reinvestment risk arises when the Fund is unable to reinvest income or principal at the same return it is currently earning.

10	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

Summary of the Fund (continued)

Repurchase  Agreements Risk. Repurchase agreements are agreements in which the seller of a security to the Fund agrees to repurchase that security from the Fund at a mutually agreed upon price and time. Repurchase agreements carry the risk that the counterparty may not fulfill its obligations under the agreement. This could cause the Fund's income and the value of your investment in the Fund to decline.

Rule 144A and Other Exempted Securities Risk. The Fund may invest in privately placed and other securities or instruments exempt from SEC registration (collectively “private placements”), subject to liquidity and other regulatory restrictions. In the U.S. market, private placements are typically sold only to qualified institutional buyers, or qualified purchasers, as applicable. An insufficient number of buyers interested in purchasing private placements at a particular time could adversely affect the marketability of such investments and the Fund might be unable to dispose of them promptly or at reasonable prices, subjecting the Fund to liquidity risk. The Fund may invest in private placements determined to be liquid as well as those determined to be illiquid. Even if determined to be liquid, the Fund’s holdings of private placements may increase the level of Fund illiquidity if eligible buyers are unable or unwilling to purchase them at a particular time. Issuers of Rule 144A eligible securities are required to furnish information to potential investors upon request. However, the required disclosure is much less extensive than that required of public companies and is not publicly available since the offering is not filed with the SEC. Further, issuers of Rule 144A eligible securities can require recipients of the offering information (such as the Fund) to agree contractually to keep the information confidential, which could also adversely affect the Fund’s ability to dispose of the security.

Secondary Market Trading Risk. Investors buying or selling Fund shares will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of Fund shares.

Tax Risk. Municipal securities generally pay interest that, in the opinion of bond counsel, is free from U.S. federal income tax (and in most cases, the U.S. federal alternative minimum tax). A portion of the Fund’s income from such bonds may be taxable to shareholders subject to the U.S. federal alternative minimum tax. Income from tax-exempt municipal obligations could be declared taxable, possibly retroactively, because of unfavorable changes in tax laws, adverse interpretations by the Internal Revenue Service, the non-compliant conduct of a bond issuer or under other circumstances. In such event, then the value of the security would likely fall and, as a shareholder of the Fund, you may be required to file an amended tax return and pay additional taxes.

Valuation Risk. The sales price the Fund could receive for any particular investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair value methodology that produces an estimate of the fair value of the security/instrument, which may prove to be inaccurate.

Performance Information

The Fund has not had a full calendar year of operations as of the date of this prospectus and therefore performance information is not available.

When available, the Fund intends to compare its performance to the performance of the Beta Advantage ^® Multi-Sector Municipal Bond Index.

Updated performance information can be obtained by calling toll-free 888.800.4347 or visiting columbiathreadneedleetf.com.

Fund Management

Investment Manager: Columbia Management Investment Advisers, LLC

    

Prospectus 2019

11

Columbia Multi-Sector Municipal Income ETF

Summary of the Fund (continued)

Purchase and Sale of Fund Shares

The Fund issues and redeems shares only through Authorized Participants (typically broker-dealers) in large blocks of shares, typically 50,000 shares, called Creation Units. Creation Units are issued and redeemed typically for an in-kind basket of securities. Individual shares may only be purchased and sold on a national securities exchange through a broker-dealer. Because the Fund’s shares trade at market prices rather than NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount).

Tax Information

Generally, a substantial portion of the Fund’s distributions consists of exempt-interest dividends, which are generally not taxable to you for U.S. federal income tax purposes or for purposes of the U.S. federal alternative minimum tax. A portion of the Fund’s distributions may not qualify as exempt-interest dividends; such distributions will generally be taxable to you as ordinary income or capital gains, unless you are investing through a tax-advantaged account, such as a 401(k) plan or an IRA. If you are investing through a tax-advantaged account, you may be taxed upon withdrawals from that account.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your financial advisor to recommend the Fund over another investment. Ask your financial advisor or visit your financial intermediary’s website for more information.

12	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

for the Bloomberg Barclays Municipal Bond: Electric Index and the Bloomberg Barclays Municipal Bond: Education Index, and $30 million for the Bloomberg Barclays Municipal Bond: Transportation Index; and were issued as part of a transaction of at least $100 million. At January 31, 2019, this sector held 1,534 securities.

Beta Advantage ^® Strategy to Investing in the Municipal Health Care Sector. As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the Bloomberg Barclays Municipal Bond: Hospital Index that meet the following criteria: are rated Aa2 or lower; have a remaining maturity of between and including 10 and 25 years; have an outstanding par value of at least $10 million; and were issued as part of a transaction of at least $100 million. At January 31, 2019, this sector held 1,390 securities.

Beta Advantage ^® Strategy to Investing in the Municipal High Quality Revenue Sector. As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the: (i) Bloomberg Barclays Municipal Bond: Housing Index that meet the following criteria: are rated Aa2 or higher; have a remaining maturity of between and including 2 and 15 years; have an outstanding par value of at least $10 million; and were issued as part of a transaction of at least $100 million; and (ii) the Bloomberg Barclays Municipal Bond: Water & Sewer Index that meet the following criteria: are rated A2 or higher; have a remaining maturity of between and including 2 and 10 years; have an outstanding par value of at least $15 million; and were issued as part of a transaction of at least $100 million. At January 31, 2019, this sector held 764 securities.

Beta Advantage ^® Strategy to Investing in the Municipal Core GO Sector. As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the Bloomberg Barclays Municipal Bond: GO Index that meet the following criteria: are rated Aa3 or higher; have a remaining maturity of between and including 2 and 10 years; have an outstanding par value of at least $15 million for local GO bonds and $25 million for state GO bonds; and were issued as part of a transaction of at least $100 million. At January 31, 2019, this sector held 1,704 securities.

Beta Advantage ^® Strategy to Investing in the Municipal High Yield Sector. As part of its multi-sector approach, the Index holds, and therefore the Fund invests in, those securities included in the Bloomberg Barclays Municipal High Yield Bond Index that meet the following criteria: are rated B3 or higher; have a remaining maturity of between and including 10 and 25 years; have an outstanding par value of at least $5 million; and were issued as part of a transaction of at least $25 million. Tobacco bonds are excluded from this sector. At January 31, 2019, this sector held 424 securities.

All credit rating designations noted above are according to Bloomberg Barclays’ index rating methodology.

The Fund may invest, as part of its 80% investment policy or otherwise when the Investment Manager believes it will help the Fund track the Index, in privately placed and other securities or instruments that are purchased and sold pursuant to Rule 144A or other exemptions under the Securities Act of 1933, as amended (the 1933 Act), subject to liquidity determinations and certain regulatory restrictions.

The Index is reconstituted and rebalanced monthly on the last business day of each month.

Columbia Management expects to utilize a “representative sampling” strategy whereby the Fund invests in only some of the component securities of the Index that, collectively, are believed by the Investment Manager to generally reflect the same risk and return characteristics of the Index. As such, the Fund may not track the Index with the same degree of accuracy as would an investment vehicle replicating (or investing in) the entire Index. Through its representative sampling investment technique, the Fund expects to typically hold approximately 120 bonds, which is a small subset of the total number of holdings in the Index, which, as of January 31, 2019, had 5,816 holdings. As Fund assets under management increase, the Fund’s holdings will likely increase. There may be instances in which the Fund may overweight (or underweight) an Index holding, purchase (or sell) instruments not in the Index as a substitute for one or more securities in the Index or utilize various combinations of other available investment techniques in seeking to replicate the performance of the Index. Under certain circumstances or conditions or due to other factors, including, for example, the size of the Fund (in terms of assets under management), the Fund may increase its number of holdings beyond the typical number of holdings stated above.

14	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

The Fund may sell securities or other holdings that are represented in the Index or purchase securities or make other investments that are not yet represented in the Index in anticipation of their removal from or addition to the Index by the Index Provider.

The Investment Manager does not invest the Fund’s assets based on its view of the investment merits of a particular security or company, neither does it conduct fundamental investment research or analysis, nor seek to forecast or otherwise consider market movements, conditions or trends in managing the Fund’s assets. The Fund pursues its investment objective of correlating performance with the Index regardless of market conditions and does not take defensive positions.

To the extent the Index is concentrated in a particular sector or industry, the Fund will necessarily be concentrated in that sector or industry.

The Fund’s investment policy with respect to 80% of its assets may be changed by the Fund’s Board of Trustees without shareholder approval as long as shareholders are given 60 days’ advance written notice of the change. Additionally, shareholders will be given 60 days’ notice of any change to the Fund’s investment objective made to comply with the SEC rule governing investment company names.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Authorized Participant Concentration Risk. Only an Authorized Participant (as defined below) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units, Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund share level and at the Fund holdings level.

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.

Concentration Risk. The Fund will concentrate its investments in companies conducting business in a related group of industries within a sector(s) to approximately the same extent as the Index. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly a fund diversifies its investments, the more it spreads risk and potentially reduces the risks of loss and volatility.

Correlation/Tracking Error Risk. The Fund’s value will generally decline when the performance of the Index declines. A number of factors may affect the Fund’s ability to achieve a high degree of correlation with the Index, and there is no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation may prevent the Fund from achieving its investment objective. The factors that may adversely affect the Fund’s correlation with the Index include, among others, the size of the Fund’s portfolio, fees, expenses, transaction costs, income items, valuation methodology, accounting standards, the effectiveness of sampling techniques, changes in the Index and disruptions or illiquidity in the markets for the securities or other instruments in which the Fund invests. The Fund uses a “representative sampling” approach in seeking to track the performance of the Index, which is an indexing strategy that involves investing in only some of the components of the Index that collectively are believed to have an investment profile similar to that of the Index. Because the Fund uses a representative sampling

Prospectus 2019

15

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

approach, the Fund may not track the Index with the same degree of accuracy as would an investment vehicle replicating the entire Index. In addition, the Fund may invest in securities or other instruments not included in the Index. The Fund may take or refrain from taking investment positions for various reasons, such as tax efficiency purposes, or to comply with regulatory restrictions, which may negatively affect the Fund’s correlation with the Index. The Fund may also be subject to large movements of assets into and out of the Fund, potentially resulting in the Fund being over- or under-exposed to certain components of the Index and may be impacted by Index reconstitutions and Index rebalancing events. Holding cash balances may detract from the Fund’s ability to track the Index. In addition, the Fund’s NAV may deviate from the Index if the Fund fair values a portfolio security at a price other than the price used by the Index for that security. The Fund also bears management and other expenses and transaction costs in trading securities or other instruments, which the Index does not bear. Accordingly, the Fund’s performance will likely fail to match the performance of the Index, after taking expenses into account. Any of these factors could decrease correlation between the performance of the Fund and the Index and may hinder the Fund’s ability to meet its investment objective. It is not possible to invest directly in an index.

Counterparty Risk. The risk exists that a counterparty to a transaction in a financial instrument held by the Fund or by a special purpose or structured vehicle in which the Fund invests may become insolvent or otherwise fail to perform its obligations, including making payments to the Fund, due to financial difficulties. The Fund may obtain no or limited recovery in a bankruptcy or other reorganizational proceedings, and any recovery may be significantly delayed. Transactions that the Fund enters into may involve counterparties in the financial services sector and, as a result, events affecting the financial services sector may cause the Fund’s share value to fluctuate.

Credit Risk. Credit risk is the risk that the value of debt instruments may decline if the issuer thereof defaults or otherwise becomes unable or unwilling, or is perceived to be unable or unwilling, to honor its financial obligations, such as making payments to the Fund when due. Various factors could affect the actual or perceived willingness or ability of the issuer to make timely interest or principal payments, including changes in the financial condition of the issuer or in general economic conditions. Debt instruments backed by an issuer's taxing authority may be subject to legal limits on the issuer's power to increase taxes or otherwise to raise revenue, or may be dependent on legislative appropriation or government aid. Certain debt instruments are backed only by revenues derived from a particular project or source, rather than by an issuer's taxing authority, and thus may have a greater risk of default. Rating agencies assign credit ratings to certain debt instruments to indicate their credit risk. Unless otherwise provided in the Fund’s Principal Investment Strategies, investment grade debt instruments are those rated at or above BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. Conversely, below investment grade (commonly called “high-yield” or “junk”) debt instruments are those rated below BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. A rating downgrade by such agencies can negatively impact the value of such instruments. Lower quality or unrated instruments held by the Fund may present increased credit risk as compared to higher-rated instruments. Non-investment grade debt instruments may be subject to greater price fluctuations and are more likely to experience a default than investment grade debt instruments and therefore may expose the Fund to increased credit risk.

Early Close/Late Close/Trading Halt Risk.  An exchange or market may close early, close late or issue trading halts on specific securities, or the ability to buy or sell certain securities may be restricted, which may result in the Fund being unable to buy or sell these securities. In these circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments, may incur substantial trading losses and/or may be prevented from sufficiently tracking the performance of the Index.

Fund Shares Liquidity Risk. Although the Fund’s shares are listed on the Exchange, there can be no assurance that an active, liquid or otherwise orderly trading market for shares will be established or maintained by market makers or Authorized Participants, particularly in times of stressed market conditions. In this regard, there is no obligation for market makers to make a market in the Fund’s shares or for Authorized Participants to submit purchase or redemption orders for creation units. Accordingly, if such parties determine not to perform their respective roles, this could, in turn, lead to variances between the market price of the Fund’s shares and the underlying value of those shares. Trading in Fund shares on the Exchange also may be disrupted or even halted due to market conditions or for

16	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

reasons that, in the view of the Exchange, make trading in Fund shares inadvisable. In addition, trading in Fund shares on the Exchange may be subject to trading halts caused by extraordinary market volatility pursuant to the Exchange “circuit breaker” rules. There also can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund’s shares will continue to be met or will remain unchanged.

High-Yield Investments Risk. Securities and other debt instruments held by the Fund that are rated below investment grade (commonly called “high-yield” or “junk” bonds) and unrated debt instruments of comparable quality tend to be more sensitive to credit risk than higher-rated debt instruments and may experience greater price fluctuations in response to perceived changes in the ability of the issuing entity or obligor to pay interest and principal when due than to changes in interest rates. These investments are generally more likely to experience a default than higher-rated debt instruments. High-yield debt instruments are considered to be predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal. These debt instruments typically pay a premium – a higher interest rate or yield – because of the increased risk of loss, including default. High-yield debt instruments may require a greater degree of judgment to establish a price, may be difficult to sell at the time and price the Fund desires, may carry high transaction costs, and also are generally less liquid than higher-rated debt instruments. The ratings provided by third party rating agencies are based on analyses by these ratings agencies of the credit quality of the debt instruments and may not take into account every risk related to whether interest or principal will be timely repaid. In adverse economic and other circumstances, issuers of lower-rated debt instruments are more likely to have difficulty making principal and interest payments than issuers of higher-rated debt instruments.

Index Methodology Risk. The Fund seeks performance that corresponds to the performance of the Index. There is no guarantee or assurance that the Index will achieve high, or even positive, returns. The Index may underperform more traditional indices. The Fund could lose value while other indices or measures of market performance increase in value or performance. In addition, the Fund may be subject to the risk that the index provider may not follow its stated methodology for construction of the Index and/or achieve the index provider’s intended performance objective. Errors may result in a negative performance impact to the Fund and its shareholders.

Interest Rate Risk. Interest rate risk is the risk of losses attributable to changes in interest rates. In general, if prevailing interest rates rise, the values of debt instruments tend to fall, and if interest rates fall, the values of debt instruments tend to rise. Changes in the value of a debt instrument usually will not affect the amount of income the Fund receives from it but will generally affect the value of your investment in the Fund. Changes in interest rates may also affect the liquidity of the Fund’s investments in debt instruments. In general, the longer the maturity or duration of a debt instrument, the greater its sensitivity to changes in interest rates. Interest rate declines also may increase prepayments of debt obligations, which, in turn, would increase prepayment risk (the risk that the Fund will have to reinvest the money received in securities that have lower yields). Similarly, a period of rising interest rates may negatively impact the Fund’s performance. Actions by governments and central banking authorities can result in increases in interest rates. Such actions may negatively affect the value of debt instruments held by the Fund, resulting in a negative impact on the Fund's performance and NAV. Any interest rate increases could cause the value of the Fund’s investments in debt instruments to decrease. Rising interest rates may prompt redemptions from the Fund, which may force the Fund to sell investments at a time when it is not advantageous to do so, which could result in losses.

Limitations of Intraday Indicative Value (IIV) Risk. The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the business day, (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close, which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. For example, if the Fund fair values portfolio securities, the Fund’s NAV may deviate from the approximate per share value of the Fund’s published basket of portfolio securities (i.e., the IIV), which could result in the market prices for

Prospectus 2019

17

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

Fund shares deviating from NAV. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Decreases in the number of financial institutions, including banks and broker-dealers, willing to make markets (match up sellers and buyers) in the Fund’s investments or decreases in their capacity or willingness to trade such investments may increase the Fund’s exposure to this risk. The debt market has experienced considerable growth, and financial institutions making markets in instruments purchased and sold by the Fund (e.g., bond dealers) have been subject to increased regulation. The impact of that growth and regulation on the ability and willingness of financial institutions to engage in trading or “making a market” in such instruments remains unsettled. Certain types of investments, such as lower-rated securities or those that are purchased and sold in over-the-counter markets, may be especially subject to liquidity risk. Securities or other assets in which the Fund invests may be traded in the over-the-counter market rather than on an exchange and therefore may be more difficult to purchase or sell at a fair price, which may have a negative impact on the Fund’s performance. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions of creation units, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market. In certain circumstances, the Fund might not be able to dispose of certain holdings quickly or at fair prices, preventing the Fund from tracking the Index. The municipal securities market is an over-the-counter market, which means that the Fund purchases and sells investments through municipal bond dealers. The Fund’s ability to sell investments held in its portfolio is dependent on the willingness and ability of market participants to provide bids that, in the view of portfolio management, reflect current market prices. Adverse market conditions could result in a lack of liquidity by reducing the number of ready buyers. In addition, in stressed market conditions, the market for Fund shares may become less liquid. Deterioration in the liquidity of Fund shares may adversely impact the liquidity of the Fund's underlying portfolio securities. These adverse impacts on the liquidity of Fund shares and on the liquidity of the Fund's underlying portfolio securities could in turn lead to differences between the market price of Fund shares and the underlying value of those shares.

Market Price Relative to NAV Risk. Shares of the Fund may trade at prices that vary from Fund NAV. Shares of the Fund are listed for trading on the Exchange and are bought and sold in the secondary market at market prices that may differ, in some cases significantly, from their NAV. The NAV of the Fund will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of shares, however, will generally fluctuate in response to changes in NAV, as well as the relative supply of, and demand for, Fund shares on the Exchange. The Investment Manager cannot predict whether Fund shares will trade below, at or above their NAV. Price differences may result because of, among other factors, supply and demand forces in the secondary trading market for Fund shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings. In this connection, if a shareholder purchases Fund shares at a time when the market price is at a premium to the NAV or sells shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses. Different investment strategies or techniques, including those intended to be

18	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

defensive in nature, including, as examples, stop loss orders to sell an ETF’s shares in the secondary market during negative market events or conditions, such as a “flash crash” or other market disruptions may not work as intended and may produce significant losses to investors. Investors should consult their financial intermediary prior to using any such investment strategies or techniques, or before investing in the Fund.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. The value of Fund investments may fall or fail to rise because of a variety of actual or perceived factors affecting an issuer (e.g., unfavorable news), the industry or sector in which it operates, or the market as a whole, which may reduce the value of an investment in the Fund. Accordingly, an investment in the Fund could lose money over short or long periods. The market values of the investments the Fund holds can be affected by changes or potential or perceived changes in U.S. or foreign economies, financial markets, interest rates and the liquidity of these investments, among other factors.

Money Market Fund Investment Risk. An investment in a money market fund is not a bank deposit and is not insured or guaranteed by any bank, the FDIC or any other government agency. Certain money market funds float their NAV while others seek to preserve the value of investments at a stable NAV (typically $1.00 per share). An investment in a money market fund, even an investment in a fund seeking to maintain a stable NAV per share, is not guaranteed and it is possible for the Fund to lose money by investing in these and other types of money market funds. If the liquidity of a money market fund’s portfolio deteriorates below certain levels, the money market fund may suspend redemptions (i.e., impose a redemption gate) and thereby prevent the Fund from selling its investment in the money market fund or impose a fee of up to 2% on amounts the Fund redeems from the money market fund (i.e., impose a liquidity fee). These measures may result in an investment loss or prohibit the Fund from redeeming shares when the Investment Manager would otherwise redeem shares. In addition to the fees and expenses that the Fund directly bears, the Fund indirectly bears the fees and expenses of any money market funds in which it invests, including affiliated money market funds. To the extent these fees and expenses, along with the fees and expenses of any other funds in which the Fund may invest, are expected to equal or exceed 0.01% of the Fund’s average daily net assets, they will be reflected in the Annual Fund Operating Expenses set forth in the table under “Fees and Expenses of the Fund.” By investing in a money market fund, the Fund will be exposed to the investment risks of the money market fund in direct proportion to such investment. The money market fund may not achieve its investment objective. The Fund, through its investment in the money market fund, may not achieve its investment objective. To the extent the Fund invests in instruments such as derivatives, the Fund may hold investments, which may be significant, in money market fund shares to cover its obligations resulting from the Fund’s investments in derivatives. Money market funds and the securities they invest in are subject to comprehensive regulations. The enactment of new legislation or regulations, as well as changes in interpretation and enforcement of current laws, may affect the manner of operation, performance and/or yield of money market funds.

Municipal Securities Risk. Municipal securities are debt obligations generally issued to obtain funds for various public purposes, including general financing for state and local governments, or financing for a specific project or public facility, and include obligations of the governments of the U.S. territories, commonwealths and possessions such as Guam, Puerto Rico and the U.S. Virgin Islands to the extent such obligations are exempt from state and U.S. federal income taxes. The value of municipal securities can be significantly affected by actual or expected political and legislative changes at the federal or state level. Municipal securities may be fully or partially backed by the taxing authority of the local government, by the credit of a private issuer, by the current or anticipated revenues from a specific project or specific assets or by domestic or foreign entities providing credit support, such as letters of credit, guarantees or insurance, and are generally classified into general obligation bonds and special revenue obligations. General obligation bonds are backed by an issuer's taxing authority and may be vulnerable to limits on a government's power or ability to raise revenue or increase taxes. They may also depend for payment on legislative appropriation and/or funding or other support from other governmental bodies. Revenue obligations are payable from revenues generated by a particular project or other revenue source, and are typically subject to greater risk of default than general obligation bonds because investors can look only to the revenue generated by the project or other revenue source backing the project, rather than to the general taxing authority of the state or local government issuer

Prospectus 2019

19

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

of the obligations. Because many municipal securities are issued to finance projects in sectors such as education, health care, transportation and utilities, conditions in those sectors can affect the overall municipal market. The amount of publicly available information for municipal issuers is generally less than for corporate issuers.

Issuers in a state, territory, commonwealth or possession in which the Fund invests may experience significant financial difficulties for various reasons, including as the result of events that cannot be reasonably anticipated or controlled such as social conflict or unrest, labor disruption and natural disasters. Such financial difficulties may lead to credit rating downgrade(s) of such issuers which, in turn, could affect the market values and marketability of many or all municipal obligations of issuers in such state, territory, commonwealth or possession. The value of the Fund’s shares will be negatively impacted to the extent it invests in such securities. The Fund’s annual and semiannual reports show the Fund’s investment exposures at a point in time. The risk of investing in the Fund is directly correlated to the Fund’s investment exposures.

Securities issued by a particular state and its instrumentalities are subject to the risk of unfavorable developments in such state. A municipal security can be significantly affected by adverse tax, legislative, regulatory, demographic or political changes as well as changes in a particular state's (state and its instrumentalities) financial, economic or other condition and prospects.

The Fund’s investments in municipal securities may include securities of issuers in the electric, transportation, education, and leasing sectors (collectively, these sectors compose the Municipal Core Revenue Sector), which subjects the Fund’s investments to the risks associated with those sectors, including the risk of regulatory action or policy changes by numerous governmental agencies and bodies, including federal, state, and local governmental agencies, as well as requirements imposed by private entities. Issuers in the Municipal Core Revenue Sector are subject to certain risks, including competitive pricing pressures, the rising cost of products and services (especially for companies dependent upon a relatively limited number of products or services), government regulation, obtaining and protecting patents (or the failure to do so), product liability and other similar litigation, labor disputes, lease supply and demand, and technology obsolescence, amongst other factors and conditions.

The Fund’s investments in municipal securities may include securities of issuers in the health care sector, which subjects the Fund’s investments to the risks associated with that sector, including the risk of regulatory action or policy changes by numerous governmental agencies and bodies, including federal, state, and local governmental agencies, as well as requirements imposed by private entities, such as insurance companies. A major source of revenue for the health care industry is payments from the Medicare and Medicaid programs. As a result, the industry is sensitive to legislative changes and reductions in governmental spending for such programs. Numerous other factors may affect the industry, such as general and local economic conditions, demand for services, expenses (including, among others, malpractice insurance premiums) and competition among health care providers. Additional factors also may adversely affect health care facility operations, such as adoption of legislation proposing a national health insurance program, other state or local health care reform measures, medical and technological advances that alter the need for or cost of health services or the way in which such services are delivered, changes in medical coverage that alter the traditional fee-for-service revenue stream, and efforts by employers, insurers, and governmental agencies to reduce the costs of health insurance and health care services.

New Fund Risk. The Fund is a newly-formed ETF. Accordingly, investors in the Fund bear the risk that the Fund may not be successful in implementing its investment strategy of replicating the Index, which could result in the Fund being liquidated at any time without shareholder approval and/or at a time that may not be favorable for shareholders. Such a liquidation could have negative tax consequences for shareholders.

Passive Investment Risk. The Fund is not “actively” managed and may be affected by a general decline in market segments related to its underlying index. The Fund invests in securities or instruments included in, or believed by the Investment Manager to be representative of, its underlying index, regardless of their investment merits. The Fund does not seek temporary defensive positions when markets decline or appear overvalued. The decision of whether to remove a security from an index is made by an independent index provider who is not affiliated with the Fund or the Investment Manager.

20	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

Prepayment and Extension Risk. Prepayment and extension risk is the risk that a bond or other security or investment might, in the case of prepayment risk, be called or otherwise converted, prepaid or redeemed before maturity and, in the case of extension risk, that the investment might not be called as expected. In the case of prepayment risk, if the investment is converted, prepaid or redeemed before maturity, the portfolio managers may not be able to invest the proceeds in other investments providing as high a level of income, resulting in a reduced yield to the Fund. In the case of mortgage- or other asset-backed securities, as interest rates decrease or spreads narrow, the likelihood of prepayment increases. Conversely, extension risk is the risk that an unexpected rise in interest rates will extend the life of a mortgage- or other asset-backed security beyond the prepayment time. If the Fund's investments are locked in at a lower interest rate for a longer period of time, the portfolio managers may be unable to capitalize on securities with higher interest rates or wider spreads.

Reinvestment Risk. Reinvestment risk arises when the Fund is unable to reinvest income or principal at the same return it is currently earning.

Repurchase Agreements  Risk. Repurchase agreements are agreements in which the seller of a security to the Fund agrees to repurchase that security from the Fund at a mutually agreed upon price and time. Repurchase agreements carry the risk that the counterparty may not fulfill its obligations under the agreement. This could cause the Fund's income and the value of your investment in the Fund to decline.

Rule 144A and Other Exempted Securities Risk. The Fund may invest in privately placed and other securities or instruments exempt from SEC registration (collectively “private placements”), subject to liquidity and other regulatory restrictions. In the U.S. market, private placements are typically sold only to qualified institutional buyers, or qualified purchasers, as applicable. An insufficient number of buyers interested in purchasing private placements at a particular time could adversely affect the marketability of such investments and the Fund might be unable to dispose of them promptly or at reasonable prices, subjecting the Fund to liquidity risk (the risk that it may not be possible for the Fund to liquidate the instrument at an advantageous time or price). The Fund may invest in private placements determined to be liquid as well as those determined to be illiquid. Even if determined to be liquid, the Fund’s holdings of private placements may increase the level of Fund illiquidity if eligible buyers are unable or unwilling to purchase them at a particular time. The Fund may also have to bear the expense of registering the securities for resale and the risk of substantial delays in effecting the registration. Additionally, the purchase price and subsequent valuation of private placements typically reflect a discount, which may be significant, from the market price of comparable securities for which a more liquid market exists. Issuers of Rule 144A eligible securities are required to furnish information to potential investors upon request. However, the required disclosure is much less extensive than that required of public companies and is not publicly available since the offering is not filed with the SEC. Further, issuers of Rule 144A eligible securities can require recipients of the offering information (such as the Fund) to agree contractually to keep the information confidential, which could also adversely affect the Fund’s ability to dispose of the security.

Secondary Market Trading Risk. Investors buying or selling Fund shares will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of shares. In addition, secondary market investors will also incur the cost of the difference between the price that an investor is willing to pay for Fund shares (the bid price) and the price at which an investor is willing to sell Fund shares (the ask price). This difference in bid and ask prices is often referred to as the “spread” or “bid/ask spread.” The bid/ask spread varies over time for Fund shares based on trading volume and market liquidity, and is generally lower if the Fund’s shares have more trading volume and market liquidity and higher if the Fund’s shares have little trading volume and market liquidity. Further, increased market volatility may cause increased bid/ask spreads.

Tax Risk. Municipal securities generally pay interest that, in the opinion of bond counsel, is free from U.S. federal income tax (and in most cases, the U.S. federal alternative minimum tax). A portion of the Fund’s income from such bonds may be taxable to shareholders subject to the U.S. federal alternative minimum tax. Income from tax-exempt municipal obligations could be declared taxable, possibly retroactively, because of unfavorable changes in tax laws, adverse interpretations by the Internal Revenue Service, the non-compliant conduct of a bond issuer or under other circumstances. In such event, then the value of the security would likely fall and, as a shareholder of the Fund, you may be required to file an amended tax return and pay additional taxes.

Prospectus 2019

21

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

Valuation Risk. The sales price the Fund could receive for any particular investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair value methodology that produces an estimate of the fair value of the security/instrument, which may prove to be inaccurate.

How the Fund Differs from Traditional Mutual Funds

Redeemability. Traditional mutual fund shares may be bought from, and redeemed with, the issuing fund for cash at NAV typically calculated once at the end of each business day. Shares of the Fund, by contrast, cannot be purchased from or redeemed with the Fund except by or through Authorized Participants (defined below), and then typically for an in-kind basket of securities. In addition, the Fund issues and redeems shares on a continuous basis only in large blocks of shares, typically 50,000 shares, called Creation Units.

Exchange Listing. Unlike traditional mutual fund shares, the Fund’s shares are listed for trading on the Exchange. Investors can purchase and sell shares on the secondary market through a broker or other financial intermediary (collectively, financial intermediary(ies)). There can be no assurance that the Fund's shares will continue to trade on the Exchange or that the Fund's shares will continue to meet the requirements for listing or trading on the Exchange. See "Fund Shares Liquidity Risk" above. Investors purchasing shares in the secondary market through a brokerage account or with the assistance of a financial intermediary may be subject to brokerage commissions and charges. Secondary-market transactions do not occur at NAV, but at market prices that change throughout the day, based on the supply of, and demand for, shares and on changes in the prices of the Fund’s portfolio holdings. The market price of shares may differ from the NAV of the Fund. The difference between market price of shares and the NAV of the Fund is called a premium when the market price is above the reported NAV and called a discount when the market price is below the reported NAV. The market price of the Fund's shares may deviate significantly from the NAV of the shares, for example, in times of extreme market volatility or other conditions.

Tax Treatment. The Fund’s structure may provide for enhanced tax efficiency relative to a traditional mutual fund’s structure. Specifically, to the extent the Fund redeems its shares in kind, the distribution of portfolio securities to meet such redemption requests may mitigate certain adverse tax consequences associated with traditional mutual fund shares to continuing Fund shareholders. This is because traditional mutual funds typically sell portfolio securities to obtain cash to meet redemptions and, as necessary, may recognize taxable gains in connection with such sales. By contrast, to the extent the Fund redeems its shares in kind, as opposed to in cash, the Fund’s in-kind redemption mechanism will potentially reduce, relative to a traditional mutual fund, taxable gains resulting from redemptions. However, the Fund cannot predict to what extent, if any, it will redeem its shares in kind rather than in cash, particularly during the Fund’s growth stages when portfolio changes are more likely to be implemented within the Fund rather than through the in-kind redemption mechanism. Nor can the Fund predict the extent to which any such in-kind redemptions will reduce the taxable gain recognized in connection therewith.

ETFs generally are able to make in-kind redemptions and avoid being taxed on gain on the distributed portfolio securities at the Fund level. Because the Fund may effect redemptions partly or entirely in cash, rather than in-kind distributions, it may be required to sell portfolio securities in order to obtain the cash needed to distribute redemption proceeds. If the Fund recognizes gain on these sales, this generally will cause the Fund to recognize gain it might not otherwise have recognized, or to recognize such gain sooner than would otherwise be required if it were to distribute portfolio securities in-kind. The Fund generally intends to distribute these gains to shareholders to avoid being taxed on this gain at the Fund level and otherwise comply with the special tax rules that apply to it. This strategy may cause shareholders to be subject to tax on gains they would not otherwise be subject to, or at an earlier date than, if they had made an investment in a different ETF. Moreover, cash transactions may have to be carried out over several days if the securities market is relatively illiquid and may involve considerable brokerage fees and taxes. These brokerage fees and taxes, which will be higher than if the Fund sold and redeemed its shares principally in-kind, will be passed on to purchasers and redeemers of Creation Units in the form of creation and redemption transaction fees.

22	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

Additional Investment Strategies and Policies

This section describes certain investment strategies and policies that the Fund may utilize in pursuit of its investment objective and some additional factors and risks involved with investing in the Fund.

The Fund may consider changing the Index at any time, including if, for example: the Index becomes unavailable; the Board believes that the Index no longer serves shareholder investment needs or that another index may better serve their needs; or the financial or economic environment makes it difficult for the Fund’s investment results to correspond sufficiently to the Index. If the Fund determines to change the Index, it will assess the appropriateness of the Fund's current name in light of the new index.

20% Asset Policy

In addition to any instruments mentioned in the Fund’s principal investment strategies, the Fund may invest up to 20% of its net assets in derivatives, including forward contracts (including forward foreign currency contracts), futures (including equity futures and index futures), options (including options on futures) and swaps (including portfolio and total return swaps), as well as cash, cash equivalents and money market instruments, such as repurchase agreements and money market funds (including affiliated money market funds), for the purpose of seeking to assist the Fund in tracking the performance of the Index.

Investment Guidelines

As a general matter, and except as specifically described in the discussion of the Fund's principal investment strategies in this prospectus or as otherwise required by the Investment Company Act of 1940, as amended (the 1940 Act), the rules and regulations thereunder and any applicable exemptive relief, whenever an investment policy or limitation states a percentage of the Fund's assets that may be invested in any security or other asset or sets forth a policy regarding an investment standard, compliance with that percentage limitation or standard will be determined solely at the time of the Fund's investment in the security or asset.

Holding Other Kinds of Investments

The Fund may hold other investments that are not part of its principal investment strategies but that are for the purpose of seeking to assist the Fund in tracking the performance of the Index. These investments and their risks are described below and/or in the SAI. The Fund may choose not to invest in certain securities described in this prospectus and in the SAI, although it has the ability to do so. Information on the Fund’s holdings can be found in the Fund’s shareholder reports or by visiting columbiathreadneedleetf.com.

Transactions in Derivatives

The Fund may enter into derivative transactions. Derivatives are financial contracts whose values are, for example, based on (or “derived” from) traditional securities (such as a stock or bond), assets (such as a commodity like gold or a foreign currency), reference rates (such as the London Interbank Offered Rate (commonly known as LIBOR)) or market indices (such as the Standard & Poor's (S&P) 500 ^® Index). The use of derivatives is a highly specialized activity which involves investment techniques and risks different from those associated with ordinary portfolio securities transactions. Derivatives involve special risks and may result in losses or may limit the Fund's potential gain from favorable market movements. Derivative strategies often involve leverage, which may exaggerate a loss, potentially causing the Fund to lose more money than it would have lost had it invested in the underlying security or other asset directly. The values of derivatives may move in unexpected ways, especially in unusual market conditions, and may result in increased volatility in the value of the derivative and/or the Fund’s shares, among other consequences. The use of derivatives may also increase the amount of taxes payable by shareholders holding shares in a taxable account. Other risks arise from the Fund's potential inability to terminate or to sell derivative positions. A liquid secondary market may not always exist for the Fund's derivative positions at times when the Fund might wish to terminate or to sell such positions. Over-the-counter instruments (investments not traded on an exchange) may be illiquid, and transactions in derivatives traded in the over-the-counter market are subject to the risk that the other party will not meet its obligations. The use of derivatives also involves the risks of mispricing or improper valuation and that changes in the value of the derivative may not correlate perfectly with the underlying security, asset, reference rate or index. The Fund also may not be able to find a suitable derivative transaction counterparty, and thus

Prospectus 2019

23

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

may be unable to engage in derivative transactions when it is deemed favorable to do so, or at all. U.S. federal legislation has been enacted that provides for new clearing, margin, reporting and registration requirements for participants in the derivatives market. These changes could restrict and/or impose significant costs or other burdens upon the Fund’s participation in derivatives transactions. For more information on the risks of derivative investments and strategies, see the SAI.

Affiliated Funds Investing in the Fund

The Investment Manager or an affiliate serves as investment adviser to funds using the Columbia brand (Columbia Funds), including those that are structured as “fund-of-funds”, and provides asset-allocation services to (i) shareholders by investing in shares of other Columbia Funds, which may include the Fund (collectively referred to in this section as Underlying Funds), and (ii) discretionary managed accounts (collectively referred to as affiliated products) that invest exclusively in Underlying Funds. These affiliated products, individually or collectively, may own a significant percentage of the outstanding shares of one or more Underlying Funds, and the Investment Manager seeks to balance potential conflicts of interest between the affiliated products and the Underlying Funds in which they invest. The affiliated products’ investment in the Underlying Funds may have the effect of creating economies of scale, possibly resulting in lower expense ratios for the Underlying Funds, because the affiliated products may own substantial portions of the shares of Underlying Funds. However, redemption of Underlying Fund shares by one or more affiliated products could cause the expense ratio of an Underlying Fund to increase, as its fixed costs would be spread over a smaller asset base. Because of large positions of certain affiliated products, the Underlying Funds may experience relatively large inflows and outflows of cash due to affiliated products’ purchases and sales of Underlying Fund shares. Although the Investment Manager or its affiliate may seek to minimize the impact of these transactions where possible, for example, by structuring them over a reasonable period of time or through other measures, Underlying Funds may experience increased expenses as they buy and sell portfolio securities to manage the cash flow effect related to these transactions. Further, when the Investment Manager or its affiliate structures transactions over a reasonable period of time in order to manage the potential impact of the buy and sell decisions for the affiliated products, those affiliated products, including funds-of-funds, may pay more or less (for purchase activity), or receive more or less (for redemption activity), for shares of the Underlying Funds than if the transactions were executed in one transaction. In addition, substantial redemptions by affiliated products within a short period of time could require the Underlying Fund to liquidate positions more rapidly than would otherwise be desirable, which may have the effect of reducing or eliminating potential gain or causing it to realize a loss. In order to meet such redemptions, an Underlying Fund may be forced to sell its liquid (or more liquid) positions, leaving the Underlying Fund holding, post-redemption, a relatively larger position in illiquid investments (i.e., any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment) or less liquid securities. Substantial redemptions may also adversely affect the ability of the Underlying Fund to implement its investment strategy. The Investment Manager or its affiliate also has a conflict of interest in determining the allocation of affiliated products’ assets among the Underlying Funds, as it earns different fees from the various Underlying Funds.

Investing in Money Market Funds

The Fund may invest cash in, or hold as collateral for certain investments, shares of registered or unregistered money market funds, including funds advised by the Investment Manager or its affiliates. These funds are not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. The Fund and its shareholders indirectly bear a portion of the expenses of any money market fund or other fund in which the Fund may invest.

Fund Website and Disclosure of Portfolio Holdings

Information about the Fund may be found at columbiathreadneedleetf.com. Among other things, this website includes the Summary Prospectus, this prospectus and the SAI, the Fund’s holdings, the Fund’s last annual and semiannual reports, when available, pricing information about shares trading on the Exchange, daily NAV calculations and a historical comparison of the trading prices to NAV.

24	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

Each day the Fund is open for business, it publicly disseminates the Fund’s full portfolio holdings as of the close of the previous business day through its website at columbiathreadneedleetf.com. In addition, the In-Kind Creation Basket and In-Kind Redemption Basket, which identify the securities and share quantities which may be delivered in exchange for purchases and redemptions of Creation Units as discussed below and in the SAI, are publicly disseminated each business day prior to the opening of trading on the Exchange via the National Securities Clearing Corporation (NSCC).

Additional Information on Portfolio Turnover

A fund that replaces, or turns over, more than 100% of its investments in a year may be considered to have a high portfolio turnover rate. A high portfolio turnover rate can generate larger distributions of short-term capital gains to shareholders, which for individuals are generally taxable at higher rates than long-term capital gains for U.S. federal income tax purposes. Also, a high portfolio turnover rate can mean higher brokerage commissions and other transaction costs, which could reduce a fund’s returns. In general, the greater the volume of buying and selling by a fund, the greater the impact that brokerage commissions and other transaction costs will have on its returns. The Fund may sell securities regardless of how long they’ve been held and expects to rebalance its portfolio monthly. A higher portfolio turnover rate may reduce the relative potential tax efficiency of the Fund compared with traditional mutual funds except potentially in cases where accomplished through redemptions in kind.

Understanding Annual Fund Operating Expenses

The Fund’s annual operating expenses, as presented in the Annual Fund Operating Expenses table in the Fees and Expenses of the Fund section of this prospectus, generally are based on estimated expenses for the Fund’s current fiscal period and are expressed as a percentage (expense ratio) of the Fund’s average net assets. The expense ratio reflects the Fund’s fee arrangements as of the date of this prospectus. In general, the Fund’s expense ratio will increase as its net assets decrease, such that the Fund’s actual expense ratio may be higher than the expense ratio presented in the Annual Fund Operating Expenses table if assets fall. Any commitment by the Investment Manager and/or its affiliates to waive fees and/or cap (reimburse) expenses is expected, in part, to limit the impact of any increase in the Fund’s expense ratio that would otherwise result because of a decrease in the Fund’s assets in the current fiscal period. The Fund’s annual operating expenses are comprised of (i) investment management fees, (ii) distribution and/or service fees, and (iii) other expenses.

Primary Service Providers

The Fund enters into contractual arrangements (Service Provider Contracts) with various service providers, including, among others, the Investment Manager, the administrator, the distributor, the transfer agent and the Fund’s custodian. The Fund’s Service Provider Contracts are solely among the parties thereto. Shareholders are not parties to, or intended to be third-party beneficiaries of, any Service Provider Contracts. Further, this prospectus, the SAI and any Service Provider Contracts are not intended to give rise to any agreement, duty, special relationship or other obligation between the Fund and any investor, or give rise to any contractual, tort or other rights in any individual shareholder, group of shareholders or other person, including any right to assert a fiduciary or other duty, enforce the Service Provider Contracts against the parties or to seek any remedy thereunder, either directly or on behalf of the Fund. Nothing in the previous sentence should be read to suggest any waiver of any rights under federal or state securities laws.

The Investment Manager

Columbia Management Investment Advisers, LLC is located at 225 Franklin Street, Boston, MA 02110 and serves as investment adviser to the Columbia Funds. The Investment Manager is a registered investment adviser and a wholly-owned subsidiary of Ameriprise Financial, Inc. (Ameriprise Financial). The Investment Manager’s management experience covers all major asset classes, including equity securities, debt instruments and money market instruments. In addition to serving as an investment adviser to traditional mutual funds, exchange-traded funds and closed-end funds, the Investment Manager acts as an investment adviser for itself, its affiliates, individuals, corporations, retirement plans, private investment companies and financial intermediaries.

Prospectus 2019

25

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

Subject to oversight by the Board, the Investment Manager manages the day-to-day operations of the Fund. The Investment Manager has entered into a license agreement with Bloomberg to use the Beta Advantage ^® Multi-Sector Municipal Bond Index, as Bloomberg is the owner of the Index. The Fund is permitted to use the Index pursuant to a sub-licensing agreement with the Investment Manager.

The SEC has issued an order that permits the Investment Manager, subject to the approval of the Board, to appoint an unaffiliated subadviser or to change the terms of a subadvisory agreement, including fees paid thereunder, for the Fund without first obtaining shareholder approval, thereby avoiding the expense and delays typically associated with obtaining shareholder approval. The Investment Manager and the Columbia Funds have applied to amend this order. If issued, the updated order would permit the Investment Manager, subject to the approval of the Board, to appoint for the Fund not only unaffiliated subadvisers but also affiliated subadvisers without first obtaining shareholder approval. The Investment Manager and its affiliates may have other relationships, including significant financial relationships, with current or potential subadvisers or their affiliates, which may create certain conflicts of interest. When making recommendations to the Board to appoint or to change a subadviser, or to change the terms of a subadvisory agreement, the Investment Manager discloses to the Board the nature of any such material relationships. At present, the Investment Manager has not engaged any investment subadviser for the Fund.

The Fund pays the Investment Manager a fee for its investment advisory services. The fee is calculated as a percentage of the daily net assets of the Fund and is paid monthly. The fee is 0.28% of the Fund’s average daily net assets on all assets. In return for this fee (which is sometimes referred to as a unitary or unified fee), the Investment Manager has agreed to pay the operating costs and expenses of the Fund other than the following expenses, which will be paid by the Fund: taxes, interest incurred on borrowing by the Fund, if any, brokerage fees and commissions,  interest and fee expense related to the Fund’s participation, if any, in inverse floater structures and any other portfolio transaction expenses, infrequent and/or unusual expenses, including without limitation litigation expenses, distribution and/or service fees, expenses incurred in connection with lending securities, and any other expenses approved by the Board.

A discussion regarding the basis for the Board’s approval of the adoption of the investment management services agreement with the Investment Manager is available in the Fund’s annual report to shareholders for the fiscal period ended October 31, 2018.

Portfolio Managers

Information about the portfolio managers primarily responsible for overseeing the Fund’s investments is shown below. The SAI provides additional information about the portfolio managers, including information relating to compensation, other accounts managed by the portfolio managers, and ownership by the portfolio managers of Fund shares.

    

Ms. Stienstra joined the Investment Manager in 2007 as a senior portfolio manager. Ms. Stienstra began her investment career in 1988 and earned a B.A. from the University of Nebraska.

Mr. Myhran joined the Investment Manager in 1992. Mr. Myhran began his investment career in 1992 and earned a B.A. in business with majors in finance and quantitative analysis from the University of Wisconsin.

Other Service Providers

ALPS Distributors, Inc. (the Distributor), 1290 Broadway, Suite 1100, Denver, CO 80203, serves as the distributor of Creation Units for the Fund on an agency basis. The Distributor does not maintain a secondary market in shares.

BNY Mellon Corporation (BNY Mellon), 240 Greenwich Street, New York, New York 10286, is the administrator, fund accountant, transfer agent and custodian for the Fund.

26	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

PricewaterhouseCoopers LLP, 125 High Street, Boston, MA 02110, serves as the Fund’s independent registered public accounting firm. The independent registered public accounting firm is responsible for auditing the annual financial statements of the Fund.

Index Provider

Bloomberg Index Services Limited, with offices at 731 Lexington Avenue, New York, NY 10022, is the owner and calculator of the Beta Advantage ^® Multi-Sector Municipal Bond Index.

Other Roles and Relationships of Ameriprise Financial and its Affiliates — Certain Conflicts of Interest

The Investment Manager provides various services to the Fund and other Columbia Funds for which it is compensated. Ameriprise Financial and its affiliates may also provide other services to these funds and be compensated for them.

The Investment Manager and its affiliates may provide investment advisory and other services to other clients and customers substantially similar to those provided to the Columbia Funds. These activities, and other financial services activities of Ameriprise Financial and its affiliates, may present actual and potential conflicts of interest and introduce certain investment constraints.

Ameriprise Financial is a major financial services company, engaged in a broad range of financial activities beyond the fund-related activities of the Investment Manager, including, among others, insurance, broker-dealer (sales and trading), asset management, banking and other financial activities. These additional activities may involve multiple advisory, financial, insurance and other interests in securities and other instruments, and in companies that issue securities and other instruments, that may be bought, sold or held by the Columbia Funds.

Conflicts of interest and limitations that could affect a Columbia Fund may arise from, for example, the following:

■	compensation and other benefits received by the Investment Manager and other Ameriprise Financial affiliates related to the management/administration of a Columbia Fund and the sale of its shares;

■	the allocation of, and competition for, investment opportunities among the Fund, other funds and accounts advised/managed by the Investment Manager and other Ameriprise Financial affiliates, or Ameriprise Financial itself and its affiliates;

■	separate and potentially divergent management of a Columbia Fund and other funds and accounts advised/managed by the Investment Manager and other Ameriprise Financial affiliates;

■	regulatory and other investment restrictions on investment activities of the Investment Manager and other Ameriprise Financial affiliates and accounts advised/managed by them;

■	insurance and other relationships of Ameriprise Financial affiliates with companies and other entities in which a Columbia Fund invests; and

■	regulatory and other restrictions relating to the sharing of information between Ameriprise Financial and its affiliates, including the Investment Manager, and a Columbia Fund.

The Investment Manager and Ameriprise Financial have adopted various policies and procedures that are intended to identify, monitor and address conflicts of interest. However, there is no assurance that these policies, procedures and disclosures will be effective.

Additional information about Ameriprise Financial and the types of conflicts of interest and other matters referenced above is set forth in the Investment Management and Other Services — Other Roles and Relationships of Ameriprise Financial and its Affiliates — Certain Conflicts of Interest section of the SAI. Investors in the Columbia Funds should carefully review these disclosures and consult with their financial advisor if they have any questions.

Prospectus 2019

27

Columbia Multi-Sector Municipal Income ETF

More Information About the Fund (continued)

Certain Legal Matters

Ameriprise Financial and certain of its affiliates have historically been involved in a number of legal, arbitration and regulatory proceedings, including routine litigation, class actions and governmental actions, concerning matters arising in connection with the conduct of their business activities. Ameriprise Financial believes that the Fund is not currently the subject of, and that neither Ameriprise Financial nor any of its affiliates are the subject of, any pending legal, arbitration or regulatory proceedings that are likely to have a material adverse effect on the Fund or the ability of Ameriprise Financial or its affiliates to perform under their contracts with the Fund. Information regarding certain pending and settled legal proceedings may be found in the Fund’s shareholder reports and in the SAI. Additionally, Ameriprise Financial is required to make quarterly (10-Q), annual (10-K) and, as necessary, 8-K filings with the SEC on legal and regulatory matters that relate to Ameriprise Financial and its affiliates. Copies of these filings may be obtained by accessing the SEC website at sec.gov.

28	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

Columbia Multi-Sector Municipal Income ETF

Buying and Selling Fund Shares (continued)

Buying Fund Shares Directly from the Fund

Fund shares can only be purchased directly from the Fund by an Authorized Participant or through an Authorized Participant. An “Authorized Participant” is a participant of the Continuous Net Settlement System of the NSCC or the DTC that has executed a Participant Agreement with the Distributor, and accepted by the Transfer Agent. The Distributor will provide a list of Authorized Participants upon request. Authorized Participants may purchase Creation Units of shares, and sell individual shares on the Exchange. See Continuous Offering below.

An Authorized Participant can purchase Fund shares directly from the Fund only in Creation Units or multiples thereof. The number of shares in a Creation Unit may, but is not expected to, change over time. The Fund will not issue fractional Creation Units. Creation Units may be purchased in exchange for a basket of securities or other portfolio instruments (known as the In-Kind Creation Basket and a Cash Component ) or for an all cash payment (the Cash Value ). The Fund reserves the right to reject any purchase request at any time, for any reason, and without notice.

In-Kind Creation Basket. On each business day, prior to the opening of trading on the Exchange, BNY Mellon will post on the NSCC bulletin board the In-Kind Creation Basket for the Fund for that day. The In-Kind Creation Basket will identify the name and number of shares of each security or other instrument that must be contributed to the Fund for each Creation Unit purchased. The Fund reserves the right to accept a nonconforming or “custom” In-Kind Creation Basket under certain limited circumstances. In the case of custom orders, the order must be received by the Distributor no later than 3:00 p.m. ET.

Balancing Amount and Cash Component. In addition to the In-Kind Creation Basket, a purchaser will either pay to, or receive from, the Fund an amount of cash (“Balancing Amount”) equal to the difference between the NAV of a Creation Unit and the value of the securities in the In-Kind Creation Basket. The Balancing Amount ensures that the consideration paid by an investor for a Creation Unit is exactly equal to the value of the Creation Unit. BNY Mellon will publish, on a daily basis, information about the previous business day’s Balancing Amount. To the extent a purchaser is not owed a Balancing Amount larger than the Creation Transaction Fee, described below, the purchaser also must pay a Creation Transaction Fee, in cash. The Balancing Amount and the Creation Transaction Fee, taken together, are referred to as the Cash Component.

Cash Value. In lieu of depositing the In-Kind Creation Basket and Balancing Amount, a Fund Deposit may consist solely of cash in an amount equal to the NAV of a Creation Unit, which amount is referred to as the Cash Value. Any such purchases will be subject to a variable charge, as explained below. BNY Mellon will publish, on a daily basis, information about the Cash Value of a Creation Unit. With respect to any Fund Deposit of a Cash Value, the Cash Value and Creation Transaction Fee, taken together, are referred to as the Cash Component.

Placement of Purchase Orders. All purchase orders must be placed by or through an Authorized Participant. Purchase orders will be processed either through a manual clearing process run by DTC or through an enhanced clearing process that is available only to those DTC participants that also are participants in the Continuous Net Settlement System of the NSCC. Authorized Participants that do not use the NSCC’s enhanced clearing process may be charged a higher Creation Transaction Fee (discussed below). A purchase order must be received by the Distributor prior to the end of the business day (generally 4:00 p.m., Eastern time) and Fund Deposits of Cash Values generally must be received two hours prior (with respect to each, the “Order Cut-Off Time”) on the day the order is placed, and all other procedures set forth in the Participant Agreement must be followed, in order to receive the NAV determined on that day. On days when the NYSE or the bond markets close earlier than normal (for example, the day before a holiday), the Fund may require purchase orders to be placed earlier in the day.

Transaction Fee on Purchases of Creation Units. The Fund may impose a “Creation Transaction Fee” on purchases of Creation Units. The Creation Transaction Fee is paid to the Fund. The fee is designed to protect existing shareholders of the Fund from the costs associated with issuing Creation Units.

The Creation Transaction Fee applied to purchases of Creation Units of the Fund includes two components — a standard fee and a variable charge, as described in the table below. The variable charge does not apply to creation transactions involving only an In-Kind Creation Basket. A higher Creation Transaction Fee up to the Maximum Transaction Fee noted in the table below may be imposed on purchases outside the NSCC’s enhanced clearing

30	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

Buying and Selling Fund Shares (continued)

process, including purchases involving nonconforming In-Kind Creation Baskets or cash. Investors who, directly or indirectly, use the services of a broker or other such intermediary to compile the securities or other instruments in the In-Kind Creation Basket may pay additional fees for these services.

    

	Transaction Fees
	Standard Transaction Fee	Maximum Transaction Fee	Variable Charge
	$500*	$2,000*	Up to 2.0%

*	The Creation Transaction Fee may be as high as the Maximum Transaction Fee for transactions outside the NSCC's enhanced clearing process.

Redeeming Fund Shares Directly from the Fund

Fund shares can only be redeemed directly with the Fund by an Authorized Participant or through an Authorized Participant. An Authorized Participant may redeem Fund shares directly from the Fund only in Creation Units or multiples thereof. Creation Units may be redeemed in exchange for a “Fund Redemption.” A Fund Redemption consists of (i) a basket of securities — known as the In-Kind Redemption Basket — and Balancing Amount, or (ii) a Cash Value, in all instances equal to the value of a Creation Unit.

In-Kind Redemption Basket. If different from the In-Kind Creation Basket, the composition of the In-Kind Redemption Basket will be available on the NSCC bulletin board; otherwise, the In-Kind Creation Basket posted may be assumed to be the In-Kind Redemption Basket. The Fund may honor a redemption request with a nonconforming or “custom” In-Kind Redemption Basket under certain limited circumstances.

Balancing Amount and Cash Component. In addition to the In-Kind Redemption Basket, a redeeming investor will receive from, or pay to, the Fund a Balancing Amount in cash, depending on whether the NAV of a Creation Unit is higher or lower than the value of the securities in the In-Kind Redemption Basket. If due to receive a Balancing Amount, the amount actually received will be reduced by the amount of the applicable Redemption Transaction Fee, described below. The Balancing Amount and the Redemption Transaction Fee, taken together, are referred to as the Cash Component.

Cash Value. In lieu of the In-Kind Redemption Basket and a Balancing Amount, Creation Units may be redeemed for a Fund Redemption consisting solely of cash in an amount equal to the NAV of a Creation Unit, which amount is referred to as the Cash Value. Such redemptions will be subject to a variable charge, as explained above. The transfer agent will publish, on a daily basis, information about the Cash Value of a Creation Unit. With respect to any Fund Redemption consisting of a Cash Value, the Cash Value and Redemption Transaction Fee, taken together, are referred to as the Cash Component.

Placement of Redemption Orders. As with purchases, redemptions must be processed either through the DTC process or the enhanced NSCC process. A redemption order is deemed received on the date of transmittal if it is received by the Distributor unless the NYSE or the bond markets close early that day in which case the Fund may require redemption orders to be received earlier in the day, and if all other procedures set forth in the Participant Agreement are followed.

Transaction Fee on Redemptions of Creation Units. The Fund may impose a Redemption Transaction Fee on redemption of Creation Units. The amount of the Redemption Transaction Fee on redemptions effected through the NSCC and DTC is the same as that applied to creations and a variable charge may apply to the Cash Value. (See "Transaction Fee on Purchases of Creation Units"). The Redemption Transaction fee is paid to the Fund. The fee is designed to protect existing shareholders of the Fund from the costs associated with redeeming Creation Units.

Additional Information About Buying and Selling Fund Shares

Legal Restrictions on Transactions in Certain Securities. An investor subject to a legal restriction with respect to a particular security required to be deposited in connection with the purchase of a Creation Unit may, at the Fund’s discretion, be permitted to deposit an equivalent amount of cash in substitution for any security which would otherwise be included in the In-Kind Creation Basket applicable to the purchase of a Creation Unit.

Prospectus 2019

31

Columbia Multi-Sector Municipal Income ETF

Buying and Selling Fund Shares (continued)

Creations and redemptions of shares will be subject to applicable federal and state securities laws, including that securities accepted for deposit and securities used to satisfy redemption requests are sold in transactions that would be exempt from registration under the Securities Act of 1933, as amended (the Securities Act). The Fund (whether or not it otherwise permits cash redemptions) reserves the right to redeem Creation Units for cash to the extent that an investor could not lawfully purchase or the Fund could not lawfully deliver specific securities under such laws or the local laws of a jurisdiction in which the Fund invests. An Authorized Participant or an investor for which it is acting subject to a legal restriction with respect to a particular security included in an In-Kind Redemption Basket may be paid an equivalent amount of cash. An Authorized Participant or redeeming investor for which it is acting that is not a qualified institutional buyer (QIB) as defined in Rule 144A under the Securities Act will not be able to receive, as part of a redemption, restricted securities eligible for resale under Rule 144A.

Continuous Offering. Authorized Participants should be aware of certain legal risks unique to investors purchasing Creation Units directly from the Fund. Because shares may be issued on an ongoing basis, a “distribution” of shares could be occurring at any time. Certain activities that Authorized Participants perform with respect to the sale of shares could, depending on the circumstances, result in Authorized Participants being deemed to be a participant in the distribution, in a manner that could render Authorized Participants a statutory underwriter and subject Authorized Participants to the prospectus delivery and liability provisions of the Securities Act. For example, Authorized Participants could be deemed a statutory underwriter if Authorized Participants purchase Creation Units from the issuing Fund, break them down into the constituent shares, and sell those shares directly to customers, or if Authorized Participants choose to couple the creation of a supply of new shares with an active selling effort involving solicitation of secondary market demand for shares. Whether a person is an underwriter for purposes of the Securities Act depends upon all of the facts and circumstances pertaining to that person’s activities, and the examples mentioned here should not be considered a complete description of all the activities that could cause Authorized Participants to be deemed an underwriter.

Broker-dealer firms should also note that dealers who are not “underwriters” but are effecting transactions in shares, whether or not participating in the distribution of shares, are generally required to deliver a prospectus. This is because the prospectus delivery exemption in Section 4(3) of the Securities Act is not available in respect of such transactions as a result of Section 24(d) of the 1940 Act. As a result, broker-dealer firms should note that dealers who are not “underwriters” but are participating in a distribution (as opposed to engaging in ordinary secondary market transactions), and thus dealing with shares as part of an unsold allotment within the meaning of Section 4(3)(C) of the Securities Act, will be unable to take advantage of the prospectus delivery exemption provided by Section 4(3) of the Securities Act. For delivery of prospectuses to exchange members, the prospectus delivery mechanism of Rule 153 under the Securities Act is only available with respect to transactions on a national exchange.

Active Investors and Market Timing

The Board has determined not to adopt policies and procedures designed to prevent or monitor for frequent purchases and redemptions of the Fund’s shares because investors primarily transact in Fund shares on the secondary market. Frequent trading of shares on the secondary market does not disrupt portfolio management, increase the Fund’s trading costs, lead to realization of capital gains or otherwise harm Fund shareholders because these trades do not involve the issuance or redemption of Fund shares.

The Fund sells and redeems its shares at NAV only in Creation Units pursuant to the terms of a Participant Agreement between an Authorized Participant and the Distributor. With respect to such trades directly with the Fund to the extent effected in-kind (i.e., for securities), they generally would not cause the harmful effects that may result from frequent cash trades.

The Board recognizes that to the extent that the Fund allows or requires trades to be effected in whole or in part in cash, those trades could result in dilution to a Fund and increased transaction costs, which could negatively impact the Fund’s ability to achieve its investment objective. The Board also recognizes, however, that direct trading by Authorized Participants is critical to ensuring that the Fund’s shares trade at or close to NAV. Further, the Fund may

32	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

Buying and Selling Fund Shares (continued)

employ fair valuation pricing to minimize the potential for dilution from market timing. Moreover, the Fund imposes transaction fees on purchases and redemptions of Fund shares reflecting the fact that the Fund’s costs increase in those circumstances. The Fund reserves the right to impose additional restrictions on disruptive, excessive or short-term purchases.

Distribution and Service Fees

The Board has approved, and the Fund has adopted, a distribution and service plan (the Plan) pursuant to Rule 12b-1 under the 1940 Act. Under the Plan, the Fund is authorized to pay distribution fees to the Distributor and other firms that provide distribution and shareholder services (Service Providers). If a Service Provider provides such services, the Fund may pay fees at an annual rate not to exceed 0.25% of average daily net assets, pursuant to Rule 12b-1 under the 1940 Act.

No distribution or service fees are currently paid by the Fund, however, and there are no current plans to impose these fees. Future payments may be made under the Plan without any further shareholder approval. In the event Rule 12b-1 fees are charged, over time they would increase the cost of an investment in the Fund.

Intraday Indicative Value (IIV)

The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the Business Day (as defined below), (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close (except such quotations may be updated to reflect currency fluctuations), which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Determination of Net Asset Value

Prospectus 2019

33

Columbia Multi-Sector Municipal Income ETF

Buying and Selling Fund Shares (continued)

Equity securities are valued primarily on the basis of market quotations reported on stock exchanges and other securities markets around the world. If an equity security is listed on a national exchange, the security is valued at the closing price or, if the closing price is not readily available, the mean of the closing bid and asked prices. Certain equity securities, debt securities and other assets are valued differently. For instance, bank loans trading in the secondary market are valued primarily on the basis of indicative bids, fixed income investments maturing in 60 days or less are valued primarily using the amortized cost method, unless this methodology results in a valuation that does not approximate the market value of these securities, and those maturing in excess of 60 days are valued primarily using a market-based price obtained from a pricing service, if available. Investments in other open-end funds are valued at their published NAVs. Both market quotations and indicative bids are obtained from outside pricing services approved and monitored pursuant to a policy approved by the Fund's Board.

If a market price is not readily available or is deemed not to reflect market value, the Fund will determine the price of a portfolio security based on a determination of the security's fair value pursuant to a policy approved by the Fund's Board. In addition, the Fund may use fair valuation to price securities that trade on a foreign exchange when a significant event has occurred after the foreign exchange closes but before the time at which the Fund's share price is calculated. Foreign exchanges typically close before the time at which Fund share prices are calculated, and may be closed altogether on some days when the Fund is open. Such significant events affecting a foreign security may include, but are not limited to: (1) corporate actions, earnings announcements, litigation or other events impacting a single issuer; (2) governmental action that affects securities in one sector or country; (3) natural disasters or armed conflicts affecting a country or region; or (4) significant domestic or foreign market fluctuations. The Fund uses various criteria in determining whether a foreign security's market price is readily available and reflective of market value and, if not, the fair value of the security. To the extent the Fund has significant holdings of small cap stocks, high-yield bonds, floating rate loans, or tax-exempt, foreign or other securities that may trade infrequently, fair valuation may be used more frequently than for other funds.

Fair valuation may have the effect of reducing stale pricing arbitrage opportunities presented by the pricing of Fund shares. However, when the Fund uses fair valuation to price securities, it may value those securities higher or lower than another fund would have priced the security. Also, the use of fair valuation may cause the Fund's performance to diverge to a greater degree from the performance of various benchmarks used to compare the Fund's performance because benchmarks generally do not use fair valuation techniques. Because of the judgment involved in fair valuation decisions, there can be no assurance that the value ascribed to a particular security is accurate.

34	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

Columbia Multi-Sector Municipal Income ETF

Distributions and Taxes (continued)

Taxes

You should be aware of the following considerations applicable to the Fund:

■

The Fund intends to qualify and to be eligible for treatment each year as a regulated investment company. A regulated investment company generally is not subject to tax at the fund level on income and gains from investments that are distributed to shareholders. However, the Fund's failure to qualify for treatment as a regulated investment company would result in Fund-level taxation, and consequently, a reduction in income available for distribution to you and in the NAV of your shares. Even if the Fund qualifies for treatment as a regulated investment company, the Fund may be subject to federal excise tax on certain undistributed income or gains. For Tax-Exempt Funds: If a Tax-Exempt Fund were to fail to qualify for treatment as a regulated investment company, the Fund could not pass through the tax-exempt character of income it receives to shareholders, and any dividends paid by the Fund in respect of its net tax-exempt income in general, would be taxable to you as ordinary income.

■

Otherwise taxable distributions generally are taxable to you when paid, whether they are paid in cash or automatically reinvested in additional Fund shares. Dividends paid in January are deemed paid on December 31 of the prior year if the dividend was declared and payable to shareholders of record in October, November, or December of such prior year.

■

Distributions of the Fund's ordinary income and net short-term capital gain, if any, generally are taxable to you as ordinary income. Distributions of the Fund's net long-term capital gain, if any, generally are taxable to you as long-term capital gain. Whether capital gains are long-term or short-term is determined by how long the Fund has owned the investments that generated them, rather than how long you have owned your shares. The Fund expects to distribute net capital gains (if any) resulting from the Fund’s portfolio re-balancing, maturities, and other taxable dispositions of securities.

■

From time to time, a distribution from the Fund could constitute a return of capital. A return of capital is a return of an amount of your original investment and is not a distribution of income or capital gain from the Fund. Therefore, a return of capital is not taxable to you so long as the amount of the distribution does not exceed your tax basis in your Fund shares. A return of capital reduces your tax basis in your Fund shares, with any amounts exceeding such basis generally taxable as capital gain.

■

If you are an individual and you meet certain holding period and other requirements for your Fund shares, a portion of your distributions may be treated as “qualified dividend income” taxable at the lower net long-term capital gain rates instead of the higher ordinary income rates. Qualified dividend income is income attributable to the Fund's dividends received from certain U.S. and foreign corporations, as long as the Fund meets certain holding period and other requirements for the stock producing such dividends. The Fund does not expect a significant portion of Fund distributions to be eligible for treatment as qualified dividend income.

■	Certain high-income individuals (as well as estates and trusts) are subject to a 3.8% tax on net investment income. For individuals, the 3.8% tax applies to the lesser of (1) the amount (if any) by which the taxpayer's modified adjusted gross income exceeds certain threshold amounts or (2) the taxpayer's “net investment income.”
	Net investment income generally includes for this purpose dividends, including any capital gain dividends, paid by the Fund, and net gains recognized on the sale, redemption or exchange of shares of the Fund. For Tax-Exempt Funds: Exempt-interest dividends are not included in net investment income for this purpose, and are therefore not subject to the tax on net investment income.

■

Certain derivative instruments when held in the Fund's portfolio subject the Fund to special tax rules, the effect of which may be to, among other things, accelerate income to the Fund, defer Fund losses, cause adjustments in the holding periods of Fund portfolio securities, or convert capital gains into ordinary income, short-term capital losses into long-term capital losses or long-term capital gains into short-term capital gains. These rules could therefore affect the amount, timing and/or character of distributions to shareholders. For Tax-Exempt Funds: Derivative instruments held by a Fund may also generate taxable income to the Fund.

■	Generally, a Fund realizes a capital gain or loss on an option when the option expires, or when it is exercised, sold or otherwise terminated. However, if an option is a “section 1256 contract,” which includes most traded options

36	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

Distributions and Taxes (continued)

on a broad-based index, and the Fund holds such option at the end of its taxable year, the Fund is deemed to sell such option at fair market value at such time and recognize any gain or loss thereon, which is generally deemed to be 60% long-term and 40% short-term capital gain or loss, as described further in the SAI.

■

Income and proceeds received by the Fund from sources within foreign countries may be subject to foreign taxes. If at the end of the taxable year more than 50% of the value of the Fund's assets consists of securities of foreign corporations, and the Fund makes a special election, you will generally be required to include in your income for U.S. federal income tax purposes your share of the qualifying foreign income taxes paid by the Fund in respect of its foreign portfolio securities. You may be able to claim a foreign tax credit or deduction in respect of this amount, subject to certain limitations. There is no assurance that the Fund will make this election for a taxable year, even if it is eligible to do so.

■

For Tax-Exempt Funds: The Fund expects that distributions will consist primarily of exempt-interest dividends. Distributions of the Fund's net interest income from tax-exempt securities generally are not subject to U.S. federal income tax, but may be subject to state and local income and other taxes, as well as U.S. federal and state alternative minimum tax. Similarly, distributions of interest income that is exempt from state and local income taxes of a particular state may be subject to other taxes, including income taxes of other states, and U.S. federal and state alternative minimum tax. Certain income generated by tax-exempt securities, including capital gains on sales and market discount, is taxable. The Fund may invest a portion of its assets in securities that generate income that is not exempt from U.S. federal or state income tax. Distributions by the Fund of this income generally are taxable to you as ordinary income or long-term capital gain. Distributions of capital gains realized by the Fund, including those generated from the sale or exchange of tax-exempt securities, generally also are taxable to you. Distributions of the Fund's net short-term capital gain, if any, generally are taxable to you as ordinary income.

■

A sale, redemption or exchange of Fund shares is a taxable event. This includes redemptions where you are paid in securities. Your sales, redemptions and exchanges of Fund shares, including those paid in securities or other instruments, usually will result in a taxable capital gain or loss to you, equal to the difference between the amount you receive for your shares (or are deemed to have received in the case of exchanges) and your adjusted tax basis in the shares, which is generally the amount you paid (or are deemed to have paid in the case of exchanges) for them. Any such capital gain or loss generally will be long-term capital gain or loss if you have held your Fund shares for more than one year at the time of sale or exchange. In certain circumstances, capital losses may be converted from short-term to long-term; in other circumstances, capital losses may be disallowed under the “wash sale” rules.

■

Your broker will be responsible for furnishing tax reporting information for Fund shares held in a nonqualified account, shareholder reports, and other communications from the Fund. For sales or exchanges of Fund shares acquired in a nonqualified account after 2011, your broker is required to report basis and holding period information to you and the IRS. Your broker may offer a choice of basis calculation methods. Contact your broker to determine which basis methods are available for your account.

■

The Fund or, in the case of sales of Fund shares in the secondary market, your broker, will generally be required by federal law to withhold tax on any distributions and proceeds paid to you if you have not provided a correct TIN or have not certified to the Fund or its agent, or your broker, as the case may be, that withholding does not apply.

■

For Authorized Participants Purchasing and Redeeming in Creation Units: An Authorized Participant that exchanges equity securities for one or more Creation Units will generally recognize a gain or a loss on the exchange. The gain or loss will be equal to the difference between (i) the market value of the Creation Unit(s) at the time and, (ii) the exchanger’s aggregate basis in the securities surrendered plus (or minus) the Cash Component paid (or received). A person who redeems one or more Creation Units for equity securities will generally recognize a gain or loss equal to the difference between (i) the exchanger’s basis in the Creation Unit(s) and, (ii) the aggregate market value of the securities received plus (or minus) the Cash Component received (or paid). The IRS, however, may assert that a loss realized upon an exchange of securities for Creation Unit(s) cannot be deducted currently under the rules governing “wash sales,” or on the basis that there has been no significant change in economic position. Persons exchanging securities should consult their own tax advisors with respect to whether wash sale rules apply and when a loss might be deductible. Any capital gain or loss realized upon a

Prospectus 2019

37

Columbia Multi-Sector Municipal Income ETF

Distributions and Taxes (continued)

redemption of one or more Creation Units is generally treated as long-term capital gain or loss if the Creation Unit(s) have been held for more than one year and as short-term capital gain or loss if they have been held for one year or less. If you purchase or redeem Creation Units, you will be sent a confirmation statement showing how many shares you purchased or sold and at what price.

38	Prospectus 2019

Columbia Multi-Sector Municipal Income ETF

Premium/Discount Information

Information regarding how often the shares of the Fund traded on the Exchange at a price above (at a premium) or below (at a discount) the NAV of the Fund can be found at columbiathreadneedleetf.com/must.

Prospectus 2019

39

Columbia Multi-Sector Municipal Income ETF

[This page intentionally left blank]

  

[This page intentionally left blank]

  

[This page intentionally left blank]

Columbia Multi-Sector Municipal Income ETF

225 Franklin Street
Boston, MA 02110

Beta Advantage ^® ETFs

Columbia Sustainable Global Equity Income ETF

    

Ticker Symbol

ESGW

Columbia Sustainable International Equity Income ETF

    

Ticker Symbol

ESGN

Columbia Sustainable U.S. Equity Income ETF

    

Ticker Symbol

ESGS

This prospectus provides important information about Columbia Sustainable Global Equity Income ETF, Columbia Sustainable International Equity Income ETF and Columbia Sustainable U.S. Equity Income ETF (each a “Fund” or together the “Funds”), passively managed exchange-traded funds (each an “ETF” or together the “ETFs”) that are series of Columbia ETF Trust I (the Trust) that you should know before investing. Please read it carefully and keep it for future reference.

These securities have not been approved or disapproved by the Securities and Exchange Commission (SEC) nor has the SEC passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Shares of the Funds are listed and traded on NYSE Arca, Inc. (the Exchange).

No person has been authorized to give any information or to make any representations other than those contained in this prospectus and the Funds' Statement of Additional Information (SAI) dated March 1, 2019 (which is incorporated by reference into this prospectus and is legally a part of this prospectus) and, if given or made, such information or representations may not be relied upon as having been authorized by us.

Beta Advantage ^® ETFs

Summary of Columbia Sustainable Global Equity Income ETF

Beta Advantage ^® ETFs

Summary of Columbia Sustainable Global Equity Income ETF (continued)

The Index is owned and calculated by MSCI Inc. (MSCI or the Index Provider). The Index was developed by MSCI with input from Columbia Management Investment Advisers, LLC (the Investment Manager). The Index, which typically holds common stocks and depositary receipts, was constructed to provide exposure to U.S. and foreign (developed market) large- and mid-cap companies (located in developed markets) that are believed to offer sustainable levels of income, as well as total return opportunity.

The Index is comprised of a subset of 200 companies within the MSCI World Index. The Index was designed to reflect the performance of the top 200 U.S. and foreign large- and mid-cap companies (located in developed markets) within the MSCI World Index. The Index reflects a combination of the Beta Advantage ^® Sustainable U.S. Equity Income 100 Index (the U.S. Component) and the Beta Advantage ^® Sustainable International Equity Income 100 Index (the International Component) in a single composite index.

The U.S. Component: with a starting point of the MSCI USA Index, the U.S. Component was designed to reflect the performance of the top 100 U.S. large- and mid-cap companies, excluding real estate investment trusts (REITs). The U.S. Component typically includes common stocks.

The International Component: with a starting point of the MSCI World ex USA Index, the International Component was designed to reflect the performance of the top 100 foreign (developed markets of at least three countries other than the U.S.) large- and mid-cap companies (excluding REITs). The International Component typically includes common stocks and depositary receipts.

Each of the U.S. Component and the International Component (collectively, the Components) are constructed through the application of systematic, rules-based methodologies applied by MSCI that ranks and weights companies according to a composite factor score that focuses on security dividend yield, dividend growth, and cash-based dividend coverage ratio factors. MSCI also screens companies for "sustainability" through the application of its Environmental, Social and Governance (ESG) rating methodology that is designed to exclude companies with unfavorable corporate ESG practices. The securities within each Component are weighted based on the overall composite factor scores and dividend yield.

The Index and the Components are rebalanced on a quarterly basis in February, May, August and November. At each rebalancing, the weights of the U.S. Component and the International Component within the Index are set to match the U.S. and non-U.S. (International) weights within the MSCI World Value Index, respectively. As such, the Index's holdings in U.S. companies and non-U.S. companies are established by rule methodology, according to their weightings in the MSCI World Value Index. At January 31, 2019, the MSCI World Value Index held 60.31% in U.S. companies and 39.69% in non-U.S. companies.

The Fund uses a replication strategy to track the performance of the Index, whereby the Fund invests in or has investment exposure to substantially all of the component securities of the Index in approximately the same proportions as in the Index. However, under various circumstances, including circumstances under which it may not be possible or practicable to purchase all of the securities in the Index, or in the same weightings, the Fund may purchase or have investment exposure to a sample of the securities in the Index in proportions expected to replicate generally the performance of the Index as a whole. There may also be instances in which the Fund may overweight (or underweight) an Index holding, purchase (or sell) instruments not in the Index as a substitute for one or more securities in the Index or utilize various combinations of other available investment techniques in seeking to replicate the performance of the Index. The Fund may sell securities or other holdings that are represented in the Index or purchase securities or make other investments that are not yet represented in the Index in anticipation of their removal from or addition to the Index by MSCI.

The Investment Manager does not invest the Fund’s assets based on its view of the investment merits of a particular security or company, nor does it conduct fundamental investment research or analysis, or seek to forecast or otherwise consider market movements, conditions or trends in managing the Fund’s assets. The Fund pursues its investment objective of correlating performance with the Index regardless of market conditions and does not to take defensive positions.

4	Prospectus 2019

Beta Advantage ^® ETFs

Summary of Columbia Sustainable Global Equity Income ETF (continued)

The methodology applied by MSCI to select Index holdings and weightings does not set limits on sector or industry exposures. To the extent the Index is concentrated in a particular sector or industry, the Fund will necessarily be concentrated in that sector or industry. As of October 31, 2018, the Index (and therefore the Fund) was concentrated in the industrials sector.

The Fund may buy shares of Ameriprise Financial, Inc. (the Investment Manager’s parent company), if included in the Index, subject to certain restrictions.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Authorized Participant Concentration Risk. Only an Authorized Participant (as defined below) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units, Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund share level and at the Fund holdings level.

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.

Concentration Risk. The Fund will concentrate its investments in companies conducting business in a related group of industries within a sector(s) to approximately the same extent as the Index. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly a fund diversifies its investments, the more it spreads risk and potentially reduces the risks of loss and volatility.

Correlation/Tracking Error Risk. The Fund’s value will generally decline when the performance of the Index declines. A number of factors may affect the Fund’s ability to achieve a high degree of correlation with the Index, and there is no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation may prevent the Fund from achieving its investment objective. The Fund also bears management and other expenses and transaction costs in trading securities or other instruments, which the Index does not bear. Accordingly, the Fund’s performance will likely fail to match the performance of the Index, after taking expenses into account. It is not possible to invest directly in an index.

Depositary Receipts Risk. Depositary receipts are receipts issued by a bank or trust company reflecting ownership of underlying securities issued by foreign companies. Some foreign securities are traded in the form of American Depositary Receipts and/or Global Depositary Receipts. Depositary receipts involve risks similar to the risks associated with investments in foreign securities, including those associated with investing in the particular country of an issuer, which may be related to the particular political, regulatory, economic, social and other conditions or events, including, for example, military confrontations, war and terrorism, occurring in the country and fluctuations in such country’s currency, as well as market risk tied to the underlying foreign company. In addition, holders of depositary receipts may have limited voting rights, may not have the same rights afforded to stockholders of a typical domestic company in the event of a corporate action, such as an acquisition, merger or rights offering, and may experience difficulty in receiving company stockholder communications. There is no guarantee that a financial institution will continue to sponsor a depositary receipt, or that a depositary receipt will continue to trade on an

Prospectus 2019

5

Beta Advantage ^® ETFs

Summary of Columbia Sustainable Global Equity Income ETF (continued)

exchange, either of which could adversely affect the liquidity, availability and pricing of the depositary receipt. Changes in foreign currency exchange rates will affect the value of depositary receipts and, therefore, may affect the value of your investment in the Fund. To the extent that the exchange price of a depositary receipt differs from the local price of the underlying security used by the Index, the Fund may be prevented from fully achieving its investment objective of tracking the performance of the Index.

Early Close/Late Close/Trading Halt Risk.  An exchange or market may close early, close late or issue trading halts on specific securities, or the ability to buy or sell certain securities may be restricted, which may result in the Fund being unable to buy or sell these securities. In these circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments, may incur substantial trading losses and/or may be prevented from sufficiently tracking the performance of the Index.

Environmental, Social and Governance Investing Risk . The Index’s environmental, social and corporate governance screening may cause the Fund to forgo certain investment opportunities, and/or forgo opportunities to gain exposure to certain industries, sectors, regions, countries and companies that could have benefited the Fund. In addition, the Fund may be required to sell a security when it might otherwise be disadvantageous for it to do so.

Foreign Securities Risk. Investments in or exposure to foreign securities involve certain risks not associated with investments in or exposure to securities of U.S. companies. Foreign securities subject the Fund to the risks associated with investing in the particular country of an issuer, including political, regulatory, economic, social, diplomatic and other conditions or events (including, for example, military confrontations, war and terrorism), occurring in the country or region, as well as risks associated with less developed custody and settlement practices. Foreign securities may be more volatile and less liquid than securities of U.S. companies, and are subject to the risks associated with potential imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the disposition of foreign securities, which could reduce the Fund’s return on such securities. The performance of the Fund may also be negatively affected by fluctuations in a foreign currency's strength or weakness relative to the U.S. dollar, particularly to the extent the Fund invests a significant percentage of its assets in foreign securities or other assets denominated in currencies other than the U.S. dollar. Additionally, the Fund’s foreign investments may trade in markets that may not be open on the same day or at the same time as the Fund, or foreign markets may close after the Fund has calculated its NAV for a given business day, which may cause a difference in the market price of such foreign securities and the value attributed to such securities by the Fund.

Fund Shares Liquidity Risk. Although the Fund’s shares are listed on the Exchange, there can be no assurance that an active, liquid or otherwise orderly trading market for shares will be established or maintained by market makers or Authorized Participants, particularly in times of stressed market conditions. In this regard, there is no obligation for market makers to make a market in the Fund’s shares or for Authorized Participants to submit purchase or redemption orders for creation units. Accordingly, if such parties determine not to perform their respective roles, this could, in turn, lead to variances between the market price of the Fund’s shares and the underlying value of those shares. Trading in Fund shares on the Exchange also may be disrupted or even halted due to market conditions or for reasons that, in the view of the Exchange, make trading in Fund shares inadvisable. In addition, trading in Fund shares on the Exchange may be subject to trading halts caused by extraordinary market volatility pursuant to the Exchange “circuit breaker” rules. There also can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund’s shares will continue to be met or will remain unchanged.

Index Methodology Risk. The Fund seeks performance that corresponds to the performance of the Index. There is no guarantee or assurance that the Index will achieve high, or even positive, returns. The Index may underperform more traditional indices. The Fund could lose value while other indices or measures of market performance increase in value or performance. In addition, the Fund may be subject to the risk that the index provider may not follow its stated methodology for construction of the Index and/or achieve the index provider’s intended performance objective. Errors may result in a negative performance impact to the Fund and its shareholders.

6	Prospectus 2019

Beta Advantage ^® ETFs

Summary of Columbia Sustainable Global Equity Income ETF (continued)

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors. The market capitalization of an issuer may also impact its risk profile. Investments in larger, more established companies may involve certain risks associated with their larger size. For instance, larger, more established companies may be less able to respond quickly to new competitive challenges, such as changes in consumer tastes or innovation from smaller competitors. Also, larger companies are sometimes less able to attain the high growth rates of successful smaller companies, especially during extended periods of economic expansion.

Limitations of Intraday Indicative Value (IIV) Risk. The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the business day, (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close, which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. For example, if the Fund fair values portfolio securities, the Fund’s NAV may deviate from the approximate per share value of the Fund’s published basket of portfolio securities (i.e., the IIV), which could result in the market prices for Fund shares deviating from NAV. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions of creation units, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market. In certain circumstances, the Fund might not be able to dispose of certain holdings quickly or at fair prices, preventing the Fund from tracking the Index. Foreign securities can present enhanced liquidity risks, including as a result of less developed custody, settlement or other practices of foreign markets. In addition, in stressed market conditions, the market for Fund shares may become less liquid. Deterioration in the liquidity of Fund shares may adversely impact the liquidity of the Fund's underlying portfolio securities. These adverse impacts on the liquidity of Fund shares and on the liquidity of the Fund's underlying portfolio securities could in turn lead to differences between the market price of Fund shares and the underlying value of those shares.

Prospectus 2019

7

Beta Advantage ^® ETFs

Summary of Columbia Sustainable Global Equity Income ETF (continued)

Market Price Relative to NAV Risk. Shares of the Fund may trade at prices that vary from Fund NAV. Shares of the Fund are listed for trading on the Exchange and are bought and sold in the secondary market at market prices that may differ, in some cases significantly, from their NAV. The NAV of the Fund will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of shares, however, will generally fluctuate in response to changes in NAV, as well as the relative supply of, and demand for, Fund shares on the Exchange. The Investment Manager cannot predict whether Fund shares will trade below, at or above their NAV. Price differences may result because of, among other factors, supply and demand forces in the secondary trading market for Fund shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings. In this connection, if a shareholder purchases Fund shares at a time when the market price is at a premium to the NAV or sells shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses. Different investment strategies or techniques, including those intended to be defensive in nature, including, as examples, stop loss orders to sell an ETF’s shares in the secondary market during negative market events or conditions, such as a “flash crash” or other market disruptions may not work as intended and may produce significant losses to investors. Investors should consult their financial intermediary prior to using any such investment strategies or techniques, or before investing in the Fund.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. An investment in the Fund could lose money over short or long periods.

Mid-Cap Company Securities Risk. Investments in mid-capitalization companies (mid-cap companies) often involve greater risks than investments in larger, more established companies (larger companies) because mid-cap companies tend to have less predictable earnings and may lack the management experience, financial resources, product diversification and competitive strengths of larger companies, and may be less liquid than the securities of larger companies.

Passive Investment Risk. The Fund is not “actively” managed and may be affected by a general decline in market segments related to its underlying index. The Fund invests in securities or instruments included in, or believed by the Investment Manager to be representative of, its underlying index, regardless of their investment merits. The Fund does not seek temporary defensive positions when markets decline or appear overvalued. The decision of whether to remove a security from the Index is made by an independent index provider who is not affiliated with the Fund or the Investment Manager.

Secondary Market Trading Risk. Investors buying or selling Fund shares will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of Fund shares.

Sector Risk. At times, the Fund may have a significant portion of its assets invested in securities of companies conducting business within one or more economic sectors, including the industrials sector. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Industrials Sector. The Fund may be more susceptible to the particular risks that may affect companies in the industrials sector than if it were invested in a wider variety of companies in unrelated sectors. Companies in the industrials sector are subject to certain risks, including changes in supply and demand for their specific product or service and for industrial sector products in general, including decline in demand for such products due to rapid technological developments and frequent new product introduction. Performance of such companies may be affected by factors including government regulation, world events and economic conditions and risks for environmental damage and product liability claims.

8	Prospectus 2019

Beta Advantage ^® ETFs

Summary of Columbia Sustainable Global Equity Income ETF (continued)

Performance Information

The following bar chart and table show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The bar chart shows how the Fund’s performance has varied for each full calendar year shown. The table below the bar chart compares the Fund’s returns for the periods shown with the index the Fund seeks to track, which provides a broad measure of market performance, as well as another measure of performance for markets in which the Fund may invest.

The after-tax returns shown in the Average Annual Total Returns table below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the table and do not reflect the impact of state, local or foreign taxes. Your actual after-tax returns will depend on your personal tax situation and may differ from those shown in the table. In addition, the after-tax returns shown in the table do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs).

Returns after taxes on distributions and sale of Fund shares are higher than before-tax returns for certain periods shown because they reflect the tax benefit of capital losses realized on the redemption of Fund shares.

The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future. Updated performance information can be obtained by calling toll-free 888.800.4347 or visiting columbiathreadneedleetf.com.

    

Year by Year Total Return (%) as of December 31 Each Year	Best and Worst Quarterly Returns During the Period Shown in the Bar Chart
	Best	4th Quarter 2017	6.80%
	Worst	4th Quarter 2018	-14.63%

  

Prospectus 2019

9

Beta Advantage ^® ETFs

Summary of Columbia Sustainable Global Equity Income ETF (continued)

Portfolio Manager		Title		Role with Fund		Managed Fund Since
Michael Barclay, CFA		Senior Portfolio Manager		Portfolio Manager		October 2018

Purchase and Sale of Fund Shares

The Fund issues and redeems shares only through Authorized Participants (typically broker-dealers) in large blocks of shares, typically 50,000 shares, called Creation Units. Creation Units are issued and redeemed typically for an in-kind basket of securities. Individual shares may only be purchased and sold on a national securities exchange through a broker-dealer. Because the Fund’s shares trade at market prices rather than NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount).

Tax Information

Distributions you receive from the Fund are taxed as ordinary income for federal income tax purposes, except to the extent designated as net capital gain, qualified dividend or return of capital and may also be subject to state or local taxes, unless you are investing through a tax-advantaged retirement plan account or are a tax-exempt investor.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your financial advisor to recommend the Fund over another investment. Ask your financial advisor or visit your financial intermediary’s website for more information.

10	Prospectus 2019

Beta Advantage ^® ETFs

Summary of Columbia Sustainable International Equity Income ETF

Beta Advantage ^® ETFs

Summary of Columbia Sustainable International Equity Income ETF (continued)

The Index is owned and calculated by MSCI Inc. (MSCI or the Index Provider). The Index was developed by MSCI with input from Columbia Management Investment Advisers, LLC (the Investment Manager). The Index, which typically holds common stocks and depositary receipts, was constructed to provide exposure to foreign large- and mid-cap companies (located in developed markets) that are believed to offer sustainable levels of income, as well as total return opportunity. The Index holds and the Fund typically invests in foreign companies in at least three countries, other than the U.S.

The Index is comprised of a subset of 100 companies within the MSCI World ex USA Index. Starting with the MSCI World ex USA Index, the Index was designed to reflect the performance of the top 100 (developed markets) foreign large- and mid-cap companies (excluding real estate investment trusts) ranked and weighted according to a composite factor score determined through the application of a systematic, rules-based methodology applied by MSCI. This methodology focuses on security dividend yield, dividend growth, and cash-based dividend coverage ratio factors. MSCI also screens companies for "sustainability" through the application of its Environmental, Social and Governance (ESG) rating methodology that is designed to exclude companies with unfavorable corporate ESG practices. The Index component securities are weighted based on the overall composite model scores and dividend yield. The Index is rebalanced on a quarterly basis in February, May, August and November.

The Fund uses a replication strategy to track the performance of the Index, whereby the Fund invests in or has investment exposure to substantially all of the component securities of the Index in approximately the same proportions as in the Index. However, under various circumstances, including circumstances under which it may not be possible or practicable to purchase all of the securities in the Index, or in the same weightings, the Fund may purchase or have investment exposure to a sample of the securities in the Index in proportions expected to replicate generally the performance of the Index as a whole. There may also be instances in which the Fund may overweight (or underweight) an Index holding, purchase (or sell) instruments not in the Index as a substitute for one or more securities in the Index or utilize various combinations of other available investment techniques in seeking to replicate the performance of the Index. The Fund may sell securities or other holdings that are represented in the Index or purchase securities or make other investments that are not yet represented in the Index in anticipation of their removal from or addition to the Index by MSCI.

The Investment Manager does not invest the Fund’s assets based on its view of the investment merits of a particular security or company, nor does it conduct fundamental investment research or analysis, or seek to forecast or otherwise consider market movements, conditions or trends in managing the Fund’s assets. The Fund pursues its investment objective of correlating performance with the Index regardless of market conditions and does not to take defensive positions.

The methodology applied by MSCI to select Index holdings and weightings does not set limits on sector or industry exposures. To the extent the Index is concentrated in a particular sector or industry, the Fund will necessarily be concentrated in that sector or industry. As of October 31, 2018, the Index (and therefore the Fund) was concentrated in the industrials and materials sectors.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Authorized Participant Concentration Risk. Only an Authorized Participant (as defined below) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units, Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund share level and at the Fund holdings level.

12	Prospectus 2019

Beta Advantage ^® ETFs

Summary of Columbia Sustainable International Equity Income ETF (continued)

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.

Concentration Risk. The Fund will concentrate its investments in companies conducting business in a related group of industries within a sector(s) to approximately the same extent as the Index. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly a fund diversifies its investments, the more it spreads risk and potentially reduces the risks of loss and volatility.

Correlation/Tracking Error Risk. The Fund’s value will generally decline when the performance of the Index declines. A number of factors may affect the Fund’s ability to achieve a high degree of correlation with the Index, and there is no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation may prevent the Fund from achieving its investment objective. The Fund also bears management and other expenses and transaction costs in trading securities or other instruments, which the Index does not bear. Accordingly, the Fund’s performance will likely fail to match the performance of the Index, after taking expenses into account. It is not possible to invest directly in an index.

Depositary Receipts Risk. Depositary receipts are receipts issued by a bank or trust company reflecting ownership of underlying securities issued by foreign companies. Some foreign securities are traded in the form of American Depositary Receipts and/or Global Depositary Receipts. Depositary receipts involve risks similar to the risks associated with investments in foreign securities, including those associated with investing in the particular country of an issuer, which may be related to the particular political, regulatory, economic, social and other conditions or events, including, for example, military confrontations, war and terrorism, occurring in the country and fluctuations in such country’s currency, as well as market risk tied to the underlying foreign company. In addition, holders of depositary receipts may have limited voting rights, may not have the same rights afforded to stockholders of a typical domestic company in the event of a corporate action, such as an acquisition, merger or rights offering, and may experience difficulty in receiving company stockholder communications. There is no guarantee that a financial institution will continue to sponsor a depositary receipt, or that a depositary receipt will continue to trade on an exchange, either of which could adversely affect the liquidity, availability and pricing of the depositary receipt. Changes in foreign currency exchange rates will affect the value of depositary receipts and, therefore, may affect the value of your investment in the Fund. To the extent that the exchange price of a depositary receipt differs from the local price of the underlying security used by the Index, the Fund may be prevented from fully achieving its investment objective of tracking the performance of the Index.

Early Close/Late Close/Trading Halt Risk.  An exchange or market may close early, close late or issue trading halts on specific securities, or the ability to buy or sell certain securities may be restricted, which may result in the Fund being unable to buy or sell these securities. In these circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments, may incur substantial trading losses and/or may be prevented from sufficiently tracking the performance of the Index.

Environmental, Social and Governance Investing Risk . The Index’s environmental, social and corporate governance screening may cause the Fund to forgo certain investment opportunities, and/or forgo opportunities to gain exposure to certain industries, sectors, regions, countries and companies that could have benefited the Fund. In addition, the Fund may be required to sell a security when it might otherwise be disadvantageous for it to do so.

Foreign Securities Risk. Investments in or exposure to foreign securities involve certain risks not associated with investments in or exposure to securities of U.S. companies. Foreign securities subject the Fund to the risks associated with investing in the particular country of an issuer, including political, regulatory, economic, social, diplomatic and other conditions or events (including, for example, military confrontations, war and terrorism), occurring in the country or region, as well as risks associated with less developed custody and settlement practices. Foreign securities may be more volatile and less liquid than securities of U.S. companies, and are subject to the

Prospectus 2019

13

Beta Advantage ^® ETFs

Summary of Columbia Sustainable International Equity Income ETF (continued)

risks associated with potential imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the disposition of foreign securities, which could reduce the Fund’s return on such securities. The performance of the Fund may also be negatively affected by fluctuations in a foreign currency's strength or weakness relative to the U.S. dollar, particularly to the extent the Fund invests a significant percentage of its assets in foreign securities or other assets denominated in currencies other than the U.S. dollar. Additionally, the Fund’s foreign investments may trade in markets that may not be open on the same day or at the same time as the Fund, or foreign markets may close after the Fund has calculated its NAV for a given business day, which may cause a difference in the market price of such foreign securities and the value attributed to such securities by the Fund.

Fund Shares Liquidity Risk. Although the Fund’s shares are listed on the Exchange, there can be no assurance that an active, liquid or otherwise orderly trading market for shares will be established or maintained by market makers or Authorized Participants, particularly in times of stressed market conditions. In this regard, there is no obligation for market makers to make a market in the Fund’s shares or for Authorized Participants to submit purchase or redemption orders for creation units. Accordingly, if such parties determine not to perform their respective roles, this could, in turn, lead to variances between the market price of the Fund’s shares and the underlying value of those shares. Trading in Fund shares on the Exchange also may be disrupted or even halted due to market conditions or for reasons that, in the view of the Exchange, make trading in Fund shares inadvisable. In addition, trading in Fund shares on the Exchange may be subject to trading halts caused by extraordinary market volatility pursuant to the Exchange “circuit breaker” rules. There also can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund’s shares will continue to be met or will remain unchanged.

Index Methodology Risk. The Fund seeks performance that corresponds to the performance of the Index. There is no guarantee or assurance that the Index will achieve high, or even positive, returns. The Index may underperform more traditional indices. The Fund could lose value while other indices or measures of market performance increase in value or performance. In addition, the Fund may be subject to the risk that the index provider may not follow its stated methodology for construction of the Index and/or achieve the index provider’s intended performance objective. Errors may result in a negative performance impact to the Fund and its shareholders.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors. The market capitalization of an issuer may also impact its risk profile. Investments in larger, more established companies may involve certain risks associated with their larger size. For instance, larger, more established companies may be less able to respond quickly to new competitive challenges, such as changes in consumer tastes or innovation from smaller competitors. Also, larger companies are sometimes less able to attain the high growth rates of successful smaller companies, especially during extended periods of economic expansion.

Limitations of Intraday Indicative Value (IIV) Risk. The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the business day, (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close, which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. For example, if the Fund fair values portfolio securities, the Fund’s NAV may deviate from the approximate per share value of the Fund’s published basket of portfolio securities (i.e., the IIV), which could result in the market prices for Fund shares deviating from NAV. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

14	Prospectus 2019

Beta Advantage ^® ETFs

Summary of Columbia Sustainable International Equity Income ETF (continued)

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions of creation units, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market. In certain circumstances, the Fund might not be able to dispose of certain holdings quickly or at fair prices, preventing the Fund from tracking the Index. Foreign securities can present enhanced liquidity risks, including as a result of less developed custody, settlement or other practices of foreign markets. In addition, in stressed market conditions, the market for Fund shares may become less liquid. Deterioration in the liquidity of Fund shares may adversely impact the liquidity of the Fund's underlying portfolio securities. These adverse impacts on the liquidity of Fund shares and on the liquidity of the Fund's underlying portfolio securities could in turn lead to differences between the market price of Fund shares and the underlying value of those shares.

Market Price Relative to NAV Risk. Shares of the Fund may trade at prices that vary from Fund NAV. Shares of the Fund are listed for trading on the Exchange and are bought and sold in the secondary market at market prices that may differ, in some cases significantly, from their NAV. The NAV of the Fund will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of shares, however, will generally fluctuate in response to changes in NAV, as well as the relative supply of, and demand for, Fund shares on the Exchange. The Investment Manager cannot predict whether Fund shares will trade below, at or above their NAV. Price differences may result because of, among other factors, supply and demand forces in the secondary trading market for Fund shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings. In this connection, if a shareholder purchases Fund shares at a time when the market price is at a premium to the NAV or sells shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses. Different investment strategies or techniques, including those intended to be defensive in nature, including, as examples, stop loss orders to sell an ETF’s shares in the secondary market during negative market events or conditions, such as a “flash crash” or other market disruptions may not work as intended and may produce significant losses to investors. Investors should consult their financial intermediary prior to using any such investment strategies or techniques, or before investing in the Fund.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. An investment in the Fund could lose money over short or long periods.

Mid-Cap Company Securities Risk. Investments in mid-capitalization companies (mid-cap companies) often involve greater risks than investments in larger, more established companies (larger companies) because mid-cap companies tend to have less predictable earnings and may lack the management experience, financial resources, product diversification and competitive strengths of larger companies, and may be less liquid than the securities of larger companies.

Prospectus 2019

15

Beta Advantage ^® ETFs

Summary of Columbia Sustainable International Equity Income ETF (continued)

Passive Investment Risk. The Fund is not “actively” managed and may be affected by a general decline in market segments related to its underlying index. The Fund invests in securities or instruments included in, or believed by the Investment Manager to be representative of, its underlying index, regardless of their investment merits. The Fund does not seek temporary defensive positions when markets decline or appear overvalued. The decision of whether to remove a security from the Index is made by an independent index provider who is not affiliated with the Fund or the Investment Manager.

Secondary Market Trading Risk. Investors buying or selling Fund shares will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of Fund shares.

Sector Risk. At times, the Fund may have a significant portion of its assets invested in securities of companies conducting business within one or more economic sectors, including the industrials and materials sectors. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Industrials Sector. The Fund may be more susceptible to the particular risks that may affect companies in the industrials sector than if it were invested in a wider variety of companies in unrelated sectors. Companies in the industrials sector are subject to certain risks, including changes in supply and demand for their specific product or service and for industrial sector products in general, including decline in demand for such products due to rapid technological developments and frequent new product introduction. Performance of such companies may be affected by factors including government regulation, world events and economic conditions and risks for environmental damage and product liability claims.

Materials Sector. The Fund may be more susceptible to the particular risks that may affect companies in the materials sector than if it were invested in a wider variety of companies in unrelated sectors. Companies in the materials sector are subject to certain risks, including that many materials companies are significantly affected by the level and volatility of commodity prices, exchange rates, import controls, increased competition, environmental policies, consumer demand, and events occurring in nature. For instance, natural events (such as earthquakes, hurricanes or fires in prime natural resource areas) and political events (such as government instability or military confrontations) can affect the value of companies involved in business activities in the materials sector. Performance of such companies may be affected by factors including, among others, that at times worldwide production of industrial materials has exceeded demand as a result of over-building or economic downturns, leading to poor investment returns or losses. Other risks may include liabilities for environmental damage and general civil liabilities, depletion of resources, and mandated expenditures for safety and pollution control. The materials sector may also be affected by economic cycles, rising interest rates, high inflation, technical progress, labor relations, legislative or regulatory changes, local and international politics, and adverse market conditions. In addition, prices of, and thus the Fund’s investments in, precious metals are considered speculative and are affected by a variety of worldwide and economic, financial and political factors. Prices of precious metals may fluctuate sharply.

Performance Information

The following bar chart and table show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The bar chart shows how the Fund’s performance has varied for each full calendar year shown. The table below the bar chart compares the Fund’s returns for the periods shown with the index the Fund seeks to track, which provides a broad measure of market performance, as well as another measure of performance for markets in which the Fund may invest.

The after-tax returns shown in the Average Annual Total Returns table below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the table and do not reflect the impact of state, local or foreign taxes. Your actual after-tax returns will depend on your personal tax situation and may differ from those shown in the table. In addition, the after-tax returns shown in the table do not

16	Prospectus 2019

Beta Advantage ^® ETFs

Summary of Columbia Sustainable International Equity Income ETF (continued)

apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs).

Returns after taxes on distributions and sale of Fund shares are higher than before-tax returns for certain periods shown because they reflect the tax benefit of capital losses realized on the redemption of Fund shares.

The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future. Updated performance information can be obtained by calling toll-free 888.800.4347 or visiting columbiathreadneedleetf.com.

    

Year by Year Total Return (%) as of December 31 Each Year	Best and Worst Quarterly Returns During the Period Shown in the Bar Chart
	Best	1st Quarter 2017	7.69%
	Worst	4th Quarter 2018	-13.09%

  

Prospectus 2019

17

Beta Advantage ^® ETFs

Summary of Columbia Sustainable International Equity Income ETF (continued)

Tax Information

Distributions you receive from the Fund are taxed as ordinary income for federal income tax purposes, except to the extent designated as net capital gain, qualified dividend or return of capital and may also be subject to state or local taxes, unless you are investing through a tax-advantaged retirement plan account or are a tax-exempt investor.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your financial advisor to recommend the Fund over another investment. Ask your financial advisor or visit your financial intermediary’s website for more information.

18	Prospectus 2019

Beta Advantage ^® ETFs

Summary of Columbia Sustainable U.S. Equity Income ETF

Beta Advantage ^® ETFs

Summary of Columbia Sustainable U.S. Equity Income ETF (continued)

The Index is owned and calculated by MSCI Inc. (MSCI or the Index Provider). The Index was developed by MSCI with input from Columbia Management Investment Advisers, LLC (the Investment Manager). The Index, which typically holds common stocks, was constructed to provide exposure to U.S. large- and mid-cap companies that are believed to offer sustainable levels of income, as well as total return opportunity.

The Index is comprised of a subset of 100 companies within the MSCI USA Index. With a starting point of the MSCI USA Index, the Index was designed to reflect the performance of the top 100 U.S. large- and mid-cap companies (excluding real estate investment trusts) ranked and weighted according to a composite factor score determined through the application of a systematic, rules-based methodology applied by MSCI. This methodology focuses on security dividend yield, dividend growth, and cash-based dividend coverage ratio factors. MSCI also screens companies for "sustainability" through the application of its Environmental, Social and Governance (ESG) rating methodology that is designed to exclude companies with unfavorable corporate ESG practices. The Index component securities are weighted based on the overall composite model scores and dividend yield. The Index is rebalanced on a quarterly basis in February, May, August and November.

The Fund uses a replication strategy to track the performance of the Index, whereby the Fund invests in or has investment exposure to substantially all of the component securities of the Index in approximately the same proportions as in the Index. However, under various circumstances, including circumstances under which it may not be possible or practicable to purchase all of the securities in the Index, or in the same weightings, the Fund may purchase or have investment exposure to a sample of the securities in the Index in proportions expected to replicate generally the performance of the Index as a whole. There may also be instances in which the Fund may overweight (or underweight) an Index holding, purchase (or sell) instruments not in the Index as a substitute for one or more securities in the Index or utilize various combinations of other available investment techniques in seeking to replicate the performance of the Index. The Fund may sell securities or other holdings that are represented in the Index or purchase securities or make other investments that are not yet represented in the Index in anticipation of their removal from or addition to the Index by MSCI.

The Investment Manager does not invest the Fund’s assets based on its view of the investment merits of a particular security or company, nor does it conduct fundamental investment research or analysis, or seek to forecast or otherwise consider market movements, conditions or trends in managing the Fund’s assets. The Fund pursues its investment objective of correlating performance with the Index regardless of market conditions and does not to take defensive positions.

The methodology applied by MSCI to select Index holdings and weightings does not set limits on sector or industry exposures. To the extent the Index is concentrated in a particular sector or industry, the Fund will necessarily be concentrated in that sector or industry.

The Fund may buy shares of Ameriprise Financial, Inc. (the Investment Manager’s parent company), if included in the Index, subject to certain restrictions.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Authorized Participant Concentration Risk. Only an Authorized Participant (as defined below) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units, Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund share level and at the Fund holdings level.

20	Prospectus 2019

Beta Advantage ^® ETFs

Summary of Columbia Sustainable U.S. Equity Income ETF (continued)

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.

Concentration Risk. The Fund will concentrate its investments in companies conducting business in a related group of industries within a sector(s) to approximately the same extent as the Index. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly a fund diversifies its investments, the more it spreads risk and potentially reduces the risks of loss and volatility.

Correlation/Tracking Error Risk. The Fund’s value will generally decline when the performance of the Index declines. A number of factors may affect the Fund’s ability to achieve a high degree of correlation with the Index, and there is no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation may prevent the Fund from achieving its investment objective. The Fund also bears management and other expenses and transaction costs in trading securities or other instruments, which the Index does not bear. Accordingly, the Fund’s performance will likely fail to match the performance of the Index, after taking expenses into account. It is not possible to invest directly in an index.

Early Close/Late Close/Trading Halt Risk.  An exchange or market may close early, close late or issue trading halts on specific securities, or the ability to buy or sell certain securities may be restricted, which may result in the Fund being unable to buy or sell these securities. In these circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments, may incur substantial trading losses and/or may be prevented from sufficiently tracking the performance of the Index.

Environmental, Social and Governance Investing Risk . The Index’s environmental, social and corporate governance screening may cause the Fund to forgo certain investment opportunities, and/or forgo opportunities to gain exposure to certain industries, sectors, regions, countries and companies that could have benefited the Fund. In addition, the Fund may be required to sell a security when it might otherwise be disadvantageous for it to do so.

Fund Shares Liquidity Risk. Although the Fund’s shares are listed on the Exchange, there can be no assurance that an active, liquid or otherwise orderly trading market for shares will be established or maintained by market makers or Authorized Participants, particularly in times of stressed market conditions. In this regard, there is no obligation for market makers to make a market in the Fund’s shares or for Authorized Participants to submit purchase or redemption orders for creation units. Accordingly, if such parties determine not to perform their respective roles, this could, in turn, lead to variances between the market price of the Fund’s shares and the underlying value of those shares. Trading in Fund shares on the Exchange also may be disrupted or even halted due to market conditions or for reasons that, in the view of the Exchange, make trading in Fund shares inadvisable. In addition, trading in Fund shares on the Exchange may be subject to trading halts caused by extraordinary market volatility pursuant to the Exchange “circuit breaker” rules. There also can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund’s shares will continue to be met or will remain unchanged.

Index Methodology Risk. The Fund seeks performance that corresponds to the performance of the Index. There is no guarantee or assurance that the Index will achieve high, or even positive, returns. The Index may underperform more traditional indices. The Fund could lose value while other indices or measures of market performance increase in value or performance. In addition, the Fund may be subject to the risk that the index provider may not follow its stated methodology for construction of the Index and/or achieve the index provider’s intended performance objective. Errors may result in a negative performance impact to the Fund and its shareholders.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors. The market capitalization of an issuer may also impact its risk profile. Investments in larger,

Prospectus 2019

21

Beta Advantage ^® ETFs

Summary of Columbia Sustainable U.S. Equity Income ETF (continued)

more established companies may involve certain risks associated with their larger size. For instance, larger, more established companies may be less able to respond quickly to new competitive challenges, such as changes in consumer tastes or innovation from smaller competitors. Also, larger companies are sometimes less able to attain the high growth rates of successful smaller companies, especially during extended periods of economic expansion.

Limitations of Intraday Indicative Value (IIV) Risk. The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the business day, (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close, which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. For example, if the Fund fair values portfolio securities, the Fund’s NAV may deviate from the approximate per share value of the Fund’s published basket of portfolio securities (i.e., the IIV), which could result in the market prices for Fund shares deviating from NAV. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Market Price Relative to NAV Risk. Shares of the Fund may trade at prices that vary from Fund NAV. Shares of the Fund are listed for trading on the Exchange and are bought and sold in the secondary market at market prices that may differ, in some cases significantly, from their NAV. The NAV of the Fund will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of shares, however, will generally fluctuate in response to changes in NAV, as well as the relative supply of, and demand for, Fund shares on the Exchange. The Investment Manager cannot predict whether Fund shares will trade below, at or above their NAV. Price differences may result because of, among other factors, supply and demand forces in the secondary trading market for Fund shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings. In this connection, if a shareholder purchases Fund shares at a time when the market price is at a premium to the NAV or sells shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses. Different investment strategies or techniques, including those intended to be defensive in nature, including, as examples, stop loss orders to sell an ETF’s shares in the secondary market during negative market events or conditions, such as a “flash crash” or other market disruptions may not work as intended and may produce significant losses to investors. Investors should consult their financial intermediary prior to using any such investment strategies or techniques, or before investing in the Fund.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. An investment in the Fund could lose money over short or long periods.

Mid-Cap Company Securities Risk. Investments in mid-capitalization companies (mid-cap companies) often involve greater risks than investments in larger, more established companies (larger companies) because mid-cap companies tend to have less predictable earnings and may lack the management experience, financial resources, product diversification and competitive strengths of larger companies, and may be less liquid than the securities of larger companies.

Passive Investment Risk. The Fund is not “actively” managed and may be affected by a general decline in market segments related to its underlying index. The Fund invests in securities or instruments included in, or believed by the Investment Manager to be representative of, its underlying index, regardless of their investment merits. The Fund does not seek temporary defensive positions when markets decline or appear overvalued. The decision of whether to remove a security from the Index is made by an independent index provider who is not affiliated with the Fund or the Investment Manager.

22	Prospectus 2019

Beta Advantage ^® ETFs

Summary of Columbia Sustainable U.S. Equity Income ETF (continued)

Secondary Market Trading Risk. Investors buying or selling Fund shares will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of Fund shares.

Performance Information

The following bar chart and table show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The bar chart shows how the Fund’s performance has varied for each full calendar year shown. The table below the bar chart compares the Fund’s returns for the periods shown with the index the Fund seeks to track, which provides a broad measure of market performance, as well as another measure of performance for markets in which the Fund may invest.

The after-tax returns shown in the Average Annual Total Returns table below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the table and do not reflect the impact of state, local or foreign taxes. Your actual after-tax returns will depend on your personal tax situation and may differ from those shown in the table. In addition, the after-tax returns shown in the table do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs).

Returns after taxes on distributions and sale of Fund shares are higher than before-tax returns for certain periods shown because they reflect the tax benefit of capital losses realized on the redemption of Fund shares.

The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future. Updated performance information can be obtained by calling toll-free 888.800.4347 or visiting columbiathreadneedleetf.com.

    

Year by Year Total Return (%) as of December 31 Each Year	Best and Worst Quarterly Returns During the Period Shown in the Bar Chart
	Best	4th Quarter 2017	7.90%
	Worst	4th Quarter 2018	-15.70%

  

Prospectus 2019

23

Beta Advantage ^® ETFs

Summary of Columbia Sustainable U.S. Equity Income ETF (continued)

Beta Advantage ^® ETFs

More Information About Columbia Sustainable Global Equity Income ETF

Investment Objective

Columbia Sustainable Global Equity Income ETF (the Fund) seeks investment results that, before fees and expenses, closely correspond to the performance of the Beta Advantage ^® Sustainable Global Equity Income 200 Index (the Index). The Fund’s investment objective is not a fundamental policy and may be changed by the Fund’s Board of Trustees without shareholder approval. Because any investment involves risk, there is no assurance the Fund’s investment objective will be achieved.

Principal Investment Strategies

The Fund uses an indexing investment approach that seeks to replicate the performance of the Index.

The Fund invests at least 80% of its assets in the component securities of the Index and depositary receipts representing such securities (or if depositary receipts are component securities of the Index, then underlying stocks of such depositary receipts).

The Index is owned and calculated by MSCI Inc. (MSCI or the Index Provider). The Index was developed by MSCI with input from Columbia Management Investment Advisers, LLC (the Investment Manager). The Index, which typically holds common stocks and depositary receipts, was constructed to provide exposure to U.S. and foreign (developed market) large- and mid-cap companies (located in developed markets) that are believed to offer sustainable levels of income, as well as total return opportunity.

The Index is comprised of a subset of 200 companies within the MSCI World Index. The Index was designed to reflect the performance of the top 200 U.S. and foreign large- and mid-cap companies (located in developed markets) within the MSCI World Index. The Index reflects a combination of the Beta Advantage ^® Sustainable U.S. Equity Income 100 Index (the U.S. Component) and the Beta Advantage ^® Sustainable International Equity Income 100 Index (the International Component) in a single composite index.

The U.S. Component: with a starting point of the MSCI USA Index, the U.S. Component was designed to reflect the performance of the top 100 U.S. large- and mid-cap companies, excluding real estate investment trusts (REITs). The U.S. Component typically includes common stocks.

The International Component: with a starting point of the MSCI World ex USA Index, the International Component was designed to reflect the performance of the top 100 foreign (developed markets of at least three countries other than the U.S.) large- and mid-cap companies (excluding REITs). The International Component typically includes common stocks and depositary receipts.

Each of the U.S. Component and the International Component (collectively, the Components) are constructed through the application of systematic, rules-based methodologies applied by MSCI that ranks and weights companies according to a composite factor score that focuses on security dividend yield, dividend growth, and cash-based dividend coverage ratio factors. MSCI also screens companies for "sustainability" through the application of its Environmental, Social and Governance (ESG) rating methodology that is designed to exclude companies with unfavorable corporate ESG practices. The securities within each Component are weighted based on the overall composite factor scores and dividend yield.

The Index and the Components are rebalanced on a quarterly basis in February, May, August and November. At each rebalancing, the weights of the U.S. Component and the International Component within the Index are set to match the U.S. and non-U.S. (International) weights within the MSCI World Value Index, respectively. As such, the Index's holdings in U.S. companies and non-U.S. companies are established by rule methodology, according to their weightings in the MSCI World Value Index. At January 31, 2017, the MSCI World Value Index held 59.35% in U.S. companies and 40.65% in non-U.S. companies.

The Fund uses a replication strategy to track the performance of the Index, whereby the Fund invests in or has investment exposure to substantially all of the component securities of the Index in approximately the same proportions as in the Index. However, under various circumstances, including circumstances under which it may not be possible or practicable to purchase all of the securities in the Index, or in the same weightings, the Fund may purchase or have investment exposure to a sample of the securities in the Index in proportions expected to replicate generally the performance of the Index as a whole. There may also be instances in which the Fund may overweight

Prospectus 2019

25

Beta Advantage ^® ETFs

More Information About Columbia Sustainable Global Equity Income ETF (continued)

(or underweight) an Index holding, purchase (or sell) instruments not in the Index as a substitute for one or more securities in the Index or utilize various combinations of other available investment techniques in seeking to replicate the performance of the Index. The Fund may sell securities or other holdings that are represented in the Index or purchase securities or make other investments that are not yet represented in the Index in anticipation of their removal from or addition to the Index by MSCI.

The Investment Manager does not invest the Fund’s assets based on its view of the investment merits of a particular security or company, nor does it conduct fundamental investment research or analysis, or seek to forecast or otherwise consider market movements, conditions or trends in managing the Fund’s assets. The Fund pursues its investment objective of correlating performance with the Index regardless of market conditions and does not to take defensive positions.

The methodology applied by MSCI to select Index holdings and weightings does not set limits on sector or industry exposures. To the extent the Index is concentrated in a particular sector or industry, the Fund will necessarily be concentrated in that sector or industry. As of October 31, 2018, the Index (and therefore the Fund) was concentrated in the industrials sector.

The Fund may buy shares of Ameriprise Financial, Inc. (the Investment Manager’s parent company), if included in the Index, subject to certain restrictions.

The Fund reserves the right to substitute a different index for the Index, without the approval of the Fund’s shareholders.

The Fund’s investment policy with respect to 80% of its assets may be changed by the Fund’s Board of Trustees without shareholder approval as long as shareholders are given 60 days’ advance written notice of the change.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Authorized Participant Concentration Risk. Only an Authorized Participant (as defined below) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units, Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund share level and at the Fund holdings level.

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.

Concentration Risk. The Fund will concentrate its investments in companies conducting business in a related group of industries within a sector(s) to approximately the same extent as the Index. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly a fund diversifies its investments, the more it spreads risk and potentially reduces the risks of loss and volatility.

Correlation/Tracking Error Risk. The Fund’s value will generally decline when the performance of the Index declines. A number of factors may affect the Fund’s ability to achieve a high degree of correlation with the Index, and there is no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation

26	Prospectus 2019

Beta Advantage ^® ETFs

More Information About Columbia Sustainable Global Equity Income ETF (continued)

may prevent the Fund from achieving its investment objective. The factors that may adversely affect the Fund’s correlation with the Index include, among others, the size of the Fund’s portfolio, fees, expenses, transaction costs, income items, valuation methodology, accounting standards, the effectiveness of sampling techniques (if applicable), changes in the Index and disruptions or illiquidity in the markets for the securities or other instruments in which the Fund invests. While the Fund typically seeks to track the performance of the Index by investing all, or substantially all, of its assets in the components of the Index in approximately the same proportion as their weighting in the Index, at times, the Fund may not have investment exposure to all components of the Index, or its weighting of investment exposure to such components may be different from that of the Index. In addition, the Fund may invest in securities or other instruments not included in the Index. The Fund may take or refrain from taking investment positions for various reasons, such as tax efficiency purposes, or to comply with regulatory restrictions, which may negatively affect the Fund’s correlation with the Index. The Fund may also be subject to large movements of assets into and out of the Fund, potentially resulting in the Fund being over- or under-exposed to certain components of the Index and may be impacted by Index reconstitutions and Index rebalancing events. Additionally, the Fund's foreign investments may trade on markets that may not be open on the same day or at the same time as the Fund, which may cause a difference between the changes in the daily performance of the Fund and changes in the level of the Index. Furthermore, the Fund may need to execute currency trades that due to regulatory, legal and operational constraints will occur at a later date than the trading of the related security. Currency holdings may be valued at a different time and at different rates than that used by the Index. Holding cash balances may detract from the Fund’s ability to track the Index. In addition, the Fund’s NAV may deviate from the Index if the Fund fair values a portfolio security at a price other than the price used by the Index for that security. The Fund also bears management and other expenses and transaction costs in trading securities or other instruments, which the Index does not bear. Accordingly, the Fund’s performance will likely fail to match the performance of the Index, after taking expenses into account. Any of these factors could decrease correlation between the performance of the Fund and the Index and may hinder the Fund’s ability to meet its investment objective. It is not possible to invest directly in an index.

Depositary Receipts Risk. Depositary receipts are receipts issued by a bank or trust company reflecting ownership of underlying securities issued by foreign companies. Some foreign securities are traded in the form of American Depositary Receipts and/or Global Depositary Receipts. Depositary receipts involve risks similar to the risks associated with investments in foreign securities, including those associated with investing in the particular country of an issuer, which may be related to the particular political, regulatory, economic, social and other conditions or events, including, for example, military confrontations, war and terrorism, occurring in the country and fluctuations in such country’s currency, as well as market risk tied to the underlying foreign company. In addition, holders of depositary receipts may have limited voting rights, may not have the same rights afforded to stockholders of a typical domestic company in the event of a corporate action, such as an acquisition, merger or rights offering, and may experience difficulty in receiving company stockholder communications. There is no guarantee that a financial institution will continue to sponsor a depositary receipt, or that a depositary receipt will continue to trade on an exchange, either of which could adversely affect the liquidity, availability and pricing of the depositary receipt. Changes in foreign currency exchange rates will affect the value of depositary receipts and, therefore, may affect the value of your investment in the Fund. To the extent that the exchange price of a depositary receipt differs from the local price of the underlying security used by the Index, the Fund may be prevented from fully achieving its investment objective of tracking the performance of the Index.

Early Close/Late Close/Trading Halt Risk.  An exchange or market may close early, close late or issue trading halts on specific securities, or the ability to buy or sell certain securities may be restricted, which may result in the Fund being unable to buy or sell these securities. In these circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments, may incur substantial trading losses and/or may be prevented from sufficiently tracking the performance of the Index.

Environmental, Social and Governance Investing Risk . The Index’s environmental, social and corporate governance screening may cause the Fund to forgo certain investment opportunities, and/or forgo opportunities to gain exposure to certain industries, sectors, regions, countries and companies that could have benefited the Fund. In addition, the Fund may be required to sell a security when it might otherwise be disadvantageous for it to do so.

Prospectus 2019

27

Beta Advantage ^® ETFs

More Information About Columbia Sustainable Global Equity Income ETF (continued)

Foreign Securities Risk. Investments in or exposure to foreign securities involve certain risks not associated with investments in or exposure to securities of U.S. companies. For example, foreign markets can be extremely volatile. Foreign securities may also be less liquid than securities of U.S. companies so that the Fund may, at times, be unable to sell foreign securities at desirable times or prices. Brokerage commissions, custodial costs and other fees are also generally higher for foreign securities. The Fund may have limited or no legal recourse in the event of default with respect to certain foreign securities, including those issued by foreign governments. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the disposition of foreign securities, which could reduce the Fund’s return on such securities. In some cases, such withholding or other taxes could potentially be confiscatory. Other risks include: possible delays in the settlement of transactions or in the payment of income; generally less publicly available information about foreign companies; the impact of economic, political, social, diplomatic or other conditions or events (including, for example, military confrontations, war and terrorism), possible seizure, expropriation or nationalization of a company or its assets or the assets of a particular investor or category of investors; accounting, auditing and financial reporting standards that may be less comprehensive and stringent than those applicable to domestic companies; the imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country; and the generally less stringent standard of care to which local agents may be held in the local markets. In addition, it may be difficult to obtain reliable information about the securities and business operations of certain foreign issuers. Governments or trade groups may compel local agents to hold securities in designated depositories that are not subject to independent evaluation. The less developed a country’s securities market is, the greater the level of risks. The risks posed by sanctions against a particular foreign country, its nationals or industries or businesses within the country may be heightened to the extent the Fund invests significantly in the affected country or region or in issuers from the affected country that depend on global markets. Additionally, investments in certain countries may subject the Fund to a number of tax rules, the application of which may be uncertain. Countries may amend or revise their existing tax laws, regulations and/or procedures in the future, possibly with retroactive effect. Changes in or uncertainties regarding the laws, regulations or procedures of a country could reduce the after-tax profits of the Fund, directly or indirectly, including by reducing the after-tax profits of companies located in such countries in which the Fund invests, or result in unexpected tax liabilities for the Fund. The performance of the Fund may also be negatively affected by fluctuations in a foreign currency's strength or weakness relative to the U.S. dollar, particularly to the extent the Fund invests a significant percentage of its assets in foreign securities or other assets denominated in currencies other than the U.S. dollar. Currency rates in foreign countries may fluctuate significantly over short or long periods of time for a number of reasons, including changes in interest rates, imposition of currency exchange controls and economic or political developments in the U.S. or abroad. The Fund may also incur currency conversion costs when converting foreign currencies into U.S. dollars and vice versa. Additionally, the Fund’s foreign investments may trade in markets that may not be open on the same day or at the same time as the Fund, or foreign markets may close after the Fund has calculated its NAV for a given business day, which may cause a difference in the market price of such foreign securities and the value attributed to such securities by the Fund.

Fund Shares Liquidity Risk. Although the Fund’s shares are listed on the Exchange, there can be no assurance that an active, liquid or otherwise orderly trading market for shares will be established or maintained by market makers or Authorized Participants, particularly in times of stressed market conditions. In this regard, there is no obligation for market makers to make a market in the Fund’s shares or for Authorized Participants to submit purchase or redemption orders for creation units. Accordingly, if such parties determine not to perform their respective roles, this could, in turn, lead to variances between the market price of the Fund’s shares and the underlying value of those shares. Trading in Fund shares on the Exchange also may be disrupted or even halted due to market conditions or for reasons that, in the view of the Exchange, make trading in Fund shares inadvisable. In addition, trading in Fund shares on the Exchange may be subject to trading halts caused by extraordinary market volatility pursuant to the Exchange “circuit breaker” rules. There also can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund’s shares will continue to be met or will remain unchanged.

Index Methodology Risk. The Fund seeks performance that corresponds to the performance of the Index. There is no guarantee or assurance that the Index will achieve high, or even positive, returns. The Index may underperform more traditional indices. The Fund could lose value while other indices or measures of market performance increase

28	Prospectus 2019

Beta Advantage ^® ETFs

More Information About Columbia Sustainable Global Equity Income ETF (continued)

in value or performance. In addition, the Fund may be subject to the risk that the index provider may not follow its stated methodology for construction of the Index and/or achieve the index provider’s intended performance objective. Errors may result in a negative performance impact to the Fund and its shareholders.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors. The market capitalization of an issuer may also impact its risk profile. Investments in larger, more established companies may involve certain risks associated with their larger size. For instance, larger, more established companies may be less able to respond quickly to new competitive challenges, such as changes in consumer tastes or innovation from smaller competitors. Also, larger companies are sometimes less able to attain the high growth rates of successful smaller companies, especially during extended periods of economic expansion.

Limitations of Intraday Indicative Value (IIV) Risk. The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the business day, (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close, which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. For example, if the Fund fair values portfolio securities, the Fund’s NAV may deviate from the approximate per share value of the Fund’s published basket of portfolio securities (i.e., the IIV), which could result in the market prices for Fund shares deviating from NAV. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions of creation units, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market. In certain circumstances, the Fund might not be able to dispose of certain holdings quickly or at fair prices, preventing the Fund from tracking the Index. Foreign securities can present enhanced liquidity risks, including as a result of less developed custody, settlement or other practices of foreign markets. In addition, in stressed market conditions, the market for Fund shares may become less liquid. Deterioration in the liquidity of Fund shares may adversely impact the liquidity of the Fund's

Prospectus 2019

29

Beta Advantage ^® ETFs

More Information About Columbia Sustainable Global Equity Income ETF (continued)

underlying portfolio securities. These adverse impacts on the liquidity of Fund shares and on the liquidity of the Fund's underlying portfolio securities could in turn lead to differences between the market price of Fund shares and the underlying value of those shares.

Market Price Relative to NAV Risk. Shares of the Fund may trade at prices that vary from Fund NAV. Shares of the Fund are listed for trading on the Exchange and are bought and sold in the secondary market at market prices that may differ, in some cases significantly, from their NAV. The NAV of the Fund will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of shares, however, will generally fluctuate in response to changes in NAV, as well as the relative supply of, and demand for, Fund shares on the Exchange. The Investment Manager cannot predict whether Fund shares will trade below, at or above their NAV. Price differences may result because of, among other factors, supply and demand forces in the secondary trading market for Fund shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings. In this connection, if a shareholder purchases Fund shares at a time when the market price is at a premium to the NAV or sells shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses. Different investment strategies or techniques, including those intended to be defensive in nature, including, as examples, stop loss orders to sell an ETF’s shares in the secondary market during negative market events or conditions, such as a “flash crash” or other market disruptions may not work as intended and may produce significant losses to investors. Investors should consult their financial intermediary prior to using any such investment strategies or techniques, or before investing in the Fund.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. The value of Fund investments may fall or fail to rise because of a variety of actual or perceived factors affecting an issuer (e.g., unfavorable news), the industry or sector in which it operates, or the market as a whole, which may reduce the value of an investment in the Fund. Accordingly, an investment in the Fund could lose money over short or long periods. The market values of the investments the Fund holds can be affected by changes or potential or perceived changes in U.S. or foreign economies, financial markets, interest rates and the liquidity of these investments, among other factors.

Mid-Cap Company Securities Risk. Securities of mid-capitalization companies (mid-cap companies) can, in certain circumstances, have more risk than securities of larger capitalization companies (larger companies). For example, mid-cap companies may be more vulnerable to market downturns and adverse business or economic events than larger companies because they may have more limited financial resources and business operations. Mid-cap companies are also more likely than larger companies to have more limited product lines and operating histories and to depend on smaller and generally less experienced management teams. Securities of mid-cap companies may trade less frequently and in smaller volumes and may fluctuate more sharply in value than securities of larger companies. When the Fund takes significant positions in mid-cap companies with limited trading volumes, the liquidation of those positions, particularly in a distressed market, could be difficult and result in Fund investment losses that would affect the value of your investment in the Fund. In addition, some mid-cap companies may not be widely followed by the investment community, which can lower the demand for their stocks.

Passive Investment Risk. The Fund is not “actively” managed and may be affected by a general decline in market segments related to its underlying index. The Fund invests in securities or instruments included in, or believed by the Investment Manager to be representative of, its underlying index, regardless of their investment merits. The Fund does not seek temporary defensive positions when markets decline or appear overvalued. The decision of whether to remove a security from the Index is made by an independent index provider who is not affiliated with the Fund or the Investment Manager.

Secondary Market Trading Risk. Investors buying or selling Fund shares will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of shares. In addition, secondary market investors will also incur the cost of the difference between the price that an investor is willing to pay for Fund shares (the bid price) and the price at which an investor is willing to sell Fund shares (the ask price). This difference in bid and ask prices is often referred to as the “spread” or “bid/ask spread.” The bid/ask spread

30	Prospectus 2019

Beta Advantage ^® ETFs

More Information About Columbia Sustainable Global Equity Income ETF (continued)

varies over time for Fund shares based on trading volume and market liquidity, and is generally lower if the Fund’s shares have more trading volume and market liquidity and higher if the Fund’s shares have little trading volume and market liquidity. Further, increased market volatility may cause increased bid/ask spreads.

Sector Risk. At times, the Fund may have a significant portion of its assets invested in securities of companies conducting business within one or more economic sectors, including the industrials sector. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Industrials Sector. The Fund may be more susceptible to the particular risks that may affect companies in the industrials sector than if it were invested in a wider variety of companies in unrelated sectors. Companies in the industrials sector are subject to certain risks, including changes in supply and demand for their specific product or service and for industrial sector products in general, including decline in demand for such products due to rapid technological developments and frequent new product introduction. Performance of such companies may be affected by factors including government regulation, world events and economic conditions and risks for environmental damage and product liability claims.

Prospectus 2019

31

Beta Advantage ^® ETFs

More Information About Columbia Sustainable International Equity Income ETF

Beta Advantage ^® ETFs

More Information About Columbia Sustainable International Equity Income ETF (continued)

The Fund reserves the right to substitute a different index for the Index, without the approval of the Fund’s shareholders.

The Fund’s investment policy with respect to 80% of its assets may be changed by the Fund’s Board of Trustees without shareholder approval as long as shareholders are given 60 days’ advance written notice of the change.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Authorized Participant Concentration Risk. Only an Authorized Participant (as defined below) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units, Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund share level and at the Fund holdings level.

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.

Concentration Risk. The Fund will concentrate its investments in companies conducting business in a related group of industries within a sector(s) to approximately the same extent as the Index. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly a fund diversifies its investments, the more it spreads risk and potentially reduces the risks of loss and volatility.

Correlation/Tracking Error Risk. The Fund’s value will generally decline when the performance of the Index declines. A number of factors may affect the Fund’s ability to achieve a high degree of correlation with the Index, and there is no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation may prevent the Fund from achieving its investment objective. The factors that may adversely affect the Fund’s correlation with the Index include, among others, the size of the Fund’s portfolio, fees, expenses, transaction costs, income items, valuation methodology, accounting standards, the effectiveness of sampling techniques (if applicable), changes in the Index and disruptions or illiquidity in the markets for the securities or other instruments in which the Fund invests. While the Fund typically seeks to track the performance of the Index by investing all, or substantially all, of its assets in the components of the Index in approximately the same proportion as their weighting in the Index, at times, the Fund may not have investment exposure to all components of the Index, or its weighting of investment exposure to such components may be different from that of the Index. In addition, the Fund may invest in securities or other instruments not included in the Index. The Fund may take or refrain from taking investment positions for various reasons, such as tax efficiency purposes, or to comply with regulatory restrictions, which may negatively affect the Fund’s correlation with the Index. The Fund may also be subject to large movements of assets into and out of the Fund, potentially resulting in the Fund being over- or under-exposed to certain components of the Index and may be impacted by Index reconstitutions and Index rebalancing events. Additionally, the Fund's foreign investments may trade on markets that may not be open on the same day or at the same time as the Fund, which may cause a difference between the changes in the daily performance of the Fund and changes in the level of the Index. Furthermore, the Fund may need to execute currency trades that due to regulatory, legal and operational constraints will occur at a later date than the trading of the related security. Currency holdings may be valued at a different time

Prospectus 2019

33

Beta Advantage ^® ETFs

More Information About Columbia Sustainable International Equity Income ETF (continued)

and at different rates than that used by the Index. Holding cash balances may detract from the Fund’s ability to track the Index. In addition, the Fund’s NAV may deviate from the Index if the Fund fair values a portfolio security at a price other than the price used by the Index for that security. The Fund also bears management and other expenses and transaction costs in trading securities or other instruments, which the Index does not bear. Accordingly, the Fund’s performance will likely fail to match the performance of the Index, after taking expenses into account. Any of these factors could decrease correlation between the performance of the Fund and the Index and may hinder the Fund’s ability to meet its investment objective. It is not possible to invest directly in an index.

Depositary Receipts Risk. Depositary receipts are receipts issued by a bank or trust company reflecting ownership of underlying securities issued by foreign companies. Some foreign securities are traded in the form of American Depositary Receipts and/or Global Depositary Receipts. Depositary receipts involve risks similar to the risks associated with investments in foreign securities, including those associated with investing in the particular country of an issuer, which may be related to the particular political, regulatory, economic, social and other conditions or events, including, for example, military confrontations, war and terrorism, occurring in the country and fluctuations in such country’s currency, as well as market risk tied to the underlying foreign company. In addition, holders of depositary receipts may have limited voting rights, may not have the same rights afforded to stockholders of a typical domestic company in the event of a corporate action, such as an acquisition, merger or rights offering, and may experience difficulty in receiving company stockholder communications. There is no guarantee that a financial institution will continue to sponsor a depositary receipt, or that a depositary receipt will continue to trade on an exchange, either of which could adversely affect the liquidity, availability and pricing of the depositary receipt. Changes in foreign currency exchange rates will affect the value of depositary receipts and, therefore, may affect the value of your investment in the Fund. To the extent that the exchange price of a depositary receipt differs from the local price of the underlying security used by the Index, the Fund may be prevented from fully achieving its investment objective of tracking the performance of the Index.

Early Close/Late Close/Trading Halt Risk.  An exchange or market may close early, close late or issue trading halts on specific securities, or the ability to buy or sell certain securities may be restricted, which may result in the Fund being unable to buy or sell these securities. In these circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments, may incur substantial trading losses and/or may be prevented from sufficiently tracking the performance of the Index.

Environmental, Social and Governance Investing Risk . The Index’s environmental, social and corporate governance screening may cause the Fund to forgo certain investment opportunities, and/or forgo opportunities to gain exposure to certain industries, sectors, regions, countries and companies that could have benefited the Fund. In addition, the Fund may be required to sell a security when it might otherwise be disadvantageous for it to do so.

Foreign Securities Risk. Investments in or exposure to foreign securities involve certain risks not associated with investments in or exposure to securities of U.S. companies. For example, foreign markets can be extremely volatile. Foreign securities may also be less liquid than securities of U.S. companies so that the Fund may, at times, be unable to sell foreign securities at desirable times or prices. Brokerage commissions, custodial costs and other fees are also generally higher for foreign securities. The Fund may have limited or no legal recourse in the event of default with respect to certain foreign securities, including those issued by foreign governments. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the disposition of foreign securities, which could reduce the Fund’s return on such securities. In some cases, such withholding or other taxes could potentially be confiscatory. Other risks include: possible delays in the settlement of transactions or in the payment of income; generally less publicly available information about foreign companies; the impact of economic, political, social, diplomatic or other conditions or events (including, for example, military confrontations, war and terrorism), possible seizure, expropriation or nationalization of a company or its assets or the assets of a particular investor or category of investors; accounting, auditing and financial reporting standards that may be less comprehensive and stringent than those applicable to domestic companies; the imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country; and the generally less stringent standard of care to which local agents may be held in the local markets. In addition, it may be difficult to obtain reliable information about the securities and business operations of certain foreign issuers. Governments or trade groups may compel local agents to hold securities in designated depositories that are

34	Prospectus 2019

Beta Advantage ^® ETFs

More Information About Columbia Sustainable International Equity Income ETF (continued)

not subject to independent evaluation. The less developed a country’s securities market is, the greater the level of risks. The risks posed by sanctions against a particular foreign country, its nationals or industries or businesses within the country may be heightened to the extent the Fund invests significantly in the affected country or region or in issuers from the affected country that depend on global markets. Additionally, investments in certain countries may subject the Fund to a number of tax rules, the application of which may be uncertain. Countries may amend or revise their existing tax laws, regulations and/or procedures in the future, possibly with retroactive effect. Changes in or uncertainties regarding the laws, regulations or procedures of a country could reduce the after-tax profits of the Fund, directly or indirectly, including by reducing the after-tax profits of companies located in such countries in which the Fund invests, or result in unexpected tax liabilities for the Fund. The performance of the Fund may also be negatively affected by fluctuations in a foreign currency's strength or weakness relative to the U.S. dollar, particularly to the extent the Fund invests a significant percentage of its assets in foreign securities or other assets denominated in currencies other than the U.S. dollar. Currency rates in foreign countries may fluctuate significantly over short or long periods of time for a number of reasons, including changes in interest rates, imposition of currency exchange controls and economic or political developments in the U.S. or abroad. The Fund may also incur currency conversion costs when converting foreign currencies into U.S. dollars and vice versa. Additionally, the Fund’s foreign investments may trade in markets that may not be open on the same day or at the same time as the Fund, or foreign markets may close after the Fund has calculated its NAV for a given business day, which may cause a difference in the market price of such foreign securities and the value attributed to such securities by the Fund.

Fund Shares Liquidity Risk. Although the Fund’s shares are listed on the Exchange, there can be no assurance that an active, liquid or otherwise orderly trading market for shares will be established or maintained by market makers or Authorized Participants, particularly in times of stressed market conditions. In this regard, there is no obligation for market makers to make a market in the Fund’s shares or for Authorized Participants to submit purchase or redemption orders for creation units. Accordingly, if such parties determine not to perform their respective roles, this could, in turn, lead to variances between the market price of the Fund’s shares and the underlying value of those shares. Trading in Fund shares on the Exchange also may be disrupted or even halted due to market conditions or for reasons that, in the view of the Exchange, make trading in Fund shares inadvisable. In addition, trading in Fund shares on the Exchange may be subject to trading halts caused by extraordinary market volatility pursuant to the Exchange “circuit breaker” rules. There also can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund’s shares will continue to be met or will remain unchanged.

Index Methodology Risk. The Fund seeks performance that corresponds to the performance of the Index. There is no guarantee or assurance that the Index will achieve high, or even positive, returns. The Index may underperform more traditional indices. The Fund could lose value while other indices or measures of market performance increase in value or performance. In addition, the Fund may be subject to the risk that the index provider may not follow its stated methodology for construction of the Index and/or achieve the index provider’s intended performance objective. Errors may result in a negative performance impact to the Fund and its shareholders.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors. The market capitalization of an issuer may also impact its risk profile. Investments in larger, more established companies may involve certain risks associated with their larger size. For instance, larger, more established companies may be less able to respond quickly to new competitive challenges, such as changes in consumer tastes or innovation from smaller competitors. Also, larger companies are sometimes less able to attain the high growth rates of successful smaller companies, especially during extended periods of economic expansion.

Limitations of Intraday Indicative Value (IIV) Risk. The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the business day, (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv)

Prospectus 2019

35

Beta Advantage ^® ETFs

More Information About Columbia Sustainable International Equity Income ETF (continued)

the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close, which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. For example, if the Fund fair values portfolio securities, the Fund’s NAV may deviate from the approximate per share value of the Fund’s published basket of portfolio securities (i.e., the IIV), which could result in the market prices for Fund shares deviating from NAV. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions of creation units, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market. In certain circumstances, the Fund might not be able to dispose of certain holdings quickly or at fair prices, preventing the Fund from tracking the Index. Foreign securities can present enhanced liquidity risks, including as a result of less developed custody, settlement or other practices of foreign markets. In addition, in stressed market conditions, the market for Fund shares may become less liquid. Deterioration in the liquidity of Fund shares may adversely impact the liquidity of the Fund's underlying portfolio securities. These adverse impacts on the liquidity of Fund shares and on the liquidity of the Fund's underlying portfolio securities could in turn lead to differences between the market price of Fund shares and the underlying value of those shares.

Market Price Relative to NAV Risk. Shares of the Fund may trade at prices that vary from Fund NAV. Shares of the Fund are listed for trading on the Exchange and are bought and sold in the secondary market at market prices that may differ, in some cases significantly, from their NAV. The NAV of the Fund will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of shares, however, will generally fluctuate in response to changes in NAV, as well as the relative supply of, and demand for, Fund shares on the Exchange. The Investment Manager cannot predict whether Fund shares will trade below, at or above their NAV. Price differences may result because of, among other factors, supply and demand forces in the secondary trading market for Fund shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings. In this connection, if a shareholder purchases Fund shares at a time when the market price is at a premium to the NAV or sells shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses. Different investment strategies or techniques, including those intended to be defensive in nature, including, as examples, stop loss orders to sell an ETF’s shares in the secondary market during negative market events or conditions, such as a “flash crash” or other market disruptions may not work as intended and may produce significant losses to investors. Investors should consult their financial intermediary prior to using any such investment strategies or techniques, or before investing in the Fund.

36	Prospectus 2019

Beta Advantage ^® ETFs

More Information About Columbia Sustainable International Equity Income ETF (continued)

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. The value of Fund investments may fall or fail to rise because of a variety of actual or perceived factors affecting an issuer (e.g., unfavorable news), the industry or sector in which it operates, or the market as a whole, which may reduce the value of an investment in the Fund. Accordingly, an investment in the Fund could lose money over short or long periods. The market values of the investments the Fund holds can be affected by changes or potential or perceived changes in U.S. or foreign economies, financial markets, interest rates and the liquidity of these investments, among other factors.

Mid-Cap Company Securities Risk. Securities of mid-capitalization companies (mid-cap companies) can, in certain circumstances, have more risk than securities of larger capitalization companies (larger companies). For example, mid-cap companies may be more vulnerable to market downturns and adverse business or economic events than larger companies because they may have more limited financial resources and business operations. Mid-cap companies are also more likely than larger companies to have more limited product lines and operating histories and to depend on smaller and generally less experienced management teams. Securities of mid-cap companies may trade less frequently and in smaller volumes and may fluctuate more sharply in value than securities of larger companies. When the Fund takes significant positions in mid-cap companies with limited trading volumes, the liquidation of those positions, particularly in a distressed market, could be difficult and result in Fund investment losses that would affect the value of your investment in the Fund. In addition, some mid-cap companies may not be widely followed by the investment community, which can lower the demand for their stocks.

Passive Investment Risk. The Fund is not “actively” managed and may be affected by a general decline in market segments related to its underlying index. The Fund invests in securities or instruments included in, or believed by the Investment Manager to be representative of, its underlying index, regardless of their investment merits. The Fund does not seek temporary defensive positions when markets decline or appear overvalued. The decision of whether to remove a security from the Index is made by an independent index provider who is not affiliated with the Fund or the Investment Manager.

Secondary Market Trading Risk. Investors buying or selling Fund shares will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of shares. In addition, secondary market investors will also incur the cost of the difference between the price that an investor is willing to pay for Fund shares (the bid price) and the price at which an investor is willing to sell Fund shares (the ask price). This difference in bid and ask prices is often referred to as the “spread” or “bid/ask spread.” The bid/ask spread varies over time for Fund shares based on trading volume and market liquidity, and is generally lower if the Fund’s shares have more trading volume and market liquidity and higher if the Fund’s shares have little trading volume and market liquidity. Further, increased market volatility may cause increased bid/ask spreads.

Sector Risk. At times, the Fund may have a significant portion of its assets invested in securities of companies conducting business within one or more economic sectors, including the industrials and materials sectors. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Industrials Sector. The Fund may be more susceptible to the particular risks that may affect companies in the industrials sector than if it were invested in a wider variety of companies in unrelated sectors. Companies in the industrials sector are subject to certain risks, including changes in supply and demand for their specific product or service and for industrial sector products in general, including decline in demand for such products due to rapid technological developments and frequent new product introduction. Performance of such companies may be affected by factors including government regulation, world events and economic conditions and risks for environmental damage and product liability claims.

Materials Sector. The Fund may be more susceptible to the particular risks that may affect companies in the materials sector than if it were invested in a wider variety of companies in unrelated sectors. Companies in the materials sector are subject to certain risks, including that many materials companies are significantly affected by

Prospectus 2019

37

Beta Advantage ^® ETFs

More Information About Columbia Sustainable International Equity Income ETF (continued)

the level and volatility of commodity prices, exchange rates, import controls, increased competition, environmental policies, consumer demand, and events occurring in nature. For instance, natural events (such as earthquakes, hurricanes or fires in prime natural resource areas) and political events (such as government instability or military confrontations) can affect the value of companies involved in business activities in the materials sector. Performance of such companies may be affected by factors including, among others, that at times worldwide production of industrial materials has exceeded demand as a result of over-building or economic downturns, leading to poor investment returns or losses. Other risks may include liabilities for environmental damage and general civil liabilities, depletion of resources, and mandated expenditures for safety and pollution control. The materials sector may also be affected by economic cycles, rising interest rates, high inflation, technical progress, labor relations, legislative or regulatory changes, local and international politics, and adverse market conditions. In addition, prices of, and thus the Fund’s investments in, precious metals are considered speculative and are affected by a variety of worldwide and economic, financial and political factors. Prices of precious metals may fluctuate sharply.

38	Prospectus 2019

Beta Advantage ^® ETFs

More Information About Columbia Sustainable U.S. Equity Income ETF

Investment Objective

Columbia Sustainable U.S. Equity Income ETF (the Fund) seeks investment results that, before fees and expenses, closely correspond to the performance of the Beta Advantage ^® Sustainable U.S. Equity Income 100  Index (the Index).

The Fund’s investment objective is not a fundamental policy and may be changed by the Fund’s Board of Trustees without shareholder approval. Because any investment involves risk, there is no assurance the Fund’s investment objective will be achieved.

Principal Investment Strategies

The Fund uses an indexing investment approach that seeks to replicate the performance of the Index.

The Fund invests at least 80% of its assets in the component securities of the Index.

The Index is owned and calculated by MSCI Inc. (MSCI or the Index Provider). The Index was developed by MSCI with input from Columbia Management Investment Advisers, LLC (the Investment Manager). The Index, which typically holds common stocks, was constructed to provide exposure to U.S. large- and mid-cap companies that are believed to offer sustainable levels of income, as well as total return opportunity.

The Index is comprised of a subset of 100 companies within the MSCI USA Index. With a starting point of the MSCI USA Index, the Index was designed to reflect the performance of the top 100 U.S. large- and mid-cap companies (excluding real estate investment trusts) ranked and weighted according to a composite factor score determined through the application of a systematic, rules-based methodology applied by MSCI. This methodology focuses on security dividend yield, dividend growth, and cash-based dividend coverage ratio factors. MSCI also screens companies for "sustainability" through the application of its Environmental, Social and Governance (ESG) rating methodology that is designed to exclude companies with unfavorable corporate ESG practices. The Index component securities are weighted based on the overall composite model scores and dividend yield. The Index is rebalanced on a quarterly basis in February, May, August and November.

The Fund uses a replication strategy to track the performance of the Index, whereby the Fund invests in or has investment exposure to substantially all of the component securities of the Index in approximately the same proportions as in the Index. However, under various circumstances, including circumstances under which it may not be possible or practicable to purchase all of the securities in the Index, or in the same weightings, the Fund may purchase or have investment exposure to a sample of the securities in the Index in proportions expected to replicate generally the performance of the Index as a whole. There may also be instances in which the Fund may overweight (or underweight) an Index holding, purchase (or sell) instruments not in the Index as a substitute for one or more securities in the Index or utilize various combinations of other available investment techniques in seeking to replicate the performance of the Index. The Fund may sell securities or other holdings that are represented in the Index or purchase securities or make other investments that are not yet represented in the Index in anticipation of their removal from or addition to the Index by MSCI.

The Investment Manager does not invest the Fund’s assets based on its view of the investment merits of a particular security or company, nor does it conduct fundamental investment research or analysis, or seek to forecast or otherwise consider market movements, conditions or trends in managing the Fund’s assets. The Fund pursues its investment objective of correlating performance with the Index regardless of market conditions and does not to take defensive positions.

The methodology applied by MSCI to select Index holdings and weightings does not set limits on sector or industry exposures. To the extent the Index is concentrated in a particular sector or industry, the Fund will necessarily be concentrated in that sector or industry.

The Fund may buy shares of Ameriprise Financial, Inc. (the Investment Manager’s parent company), if included in the Index, subject to certain restrictions.

The Fund reserves the right to substitute a different index for the Index, without the approval of the Fund’s shareholders.

Prospectus 2019

39

Beta Advantage ^® ETFs

More Information About Columbia Sustainable U.S. Equity Income ETF (continued)

The Fund’s investment policy with respect to 80% of its assets may be changed by the Fund’s Board of Trustees without shareholder approval as long as shareholders are given 60 days’ advance written notice of the change.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Authorized Participant Concentration Risk. Only an Authorized Participant (as defined below) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units, Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund share level and at the Fund holdings level.

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.

Concentration Risk. The Fund will concentrate its investments in companies conducting business in a related group of industries within a sector(s) to approximately the same extent as the Index. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than funds that invest more broadly. Generally, the more broadly a fund diversifies its investments, the more it spreads risk and potentially reduces the risks of loss and volatility.

Correlation/Tracking Error Risk. The Fund’s value will generally decline when the performance of the Index declines. A number of factors may affect the Fund’s ability to achieve a high degree of correlation with the Index, and there is no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation may prevent the Fund from achieving its investment objective. The factors that may adversely affect the Fund’s correlation with the Index include, among others, the size of the Fund’s portfolio, fees, expenses, transaction costs, income items, valuation methodology, accounting standards, the effectiveness of sampling techniques (if applicable), changes in the Index and disruptions or illiquidity in the markets for the securities or other instruments in which the Fund invests. While the Fund typically seeks to track the performance of the Index by investing all, or substantially all, of its assets in the components of the Index in approximately the same proportion as their weighting in the Index, at times, the Fund may not have investment exposure to all components of the Index, or its weighting of investment exposure to such components may be different from that of the Index. In addition, the Fund may invest in securities or other instruments not included in the Index. The Fund may take or refrain from taking investment positions for various reasons, such as tax efficiency purposes, or to comply with regulatory restrictions, which may negatively affect the Fund’s correlation with the Index. The Fund may also be subject to large movements of assets into and out of the Fund, potentially resulting in the Fund being over- or under-exposed to certain components of the Index and may be impacted by Index reconstitutions and Index rebalancing events. Holding cash balances may detract from the Fund’s ability to track the Index. In addition, the Fund’s NAV may deviate from the Index if the Fund fair values a portfolio security at a price other than the price used by the Index for that security. The Fund also bears management and other expenses and transaction costs in trading securities or other instruments, which the Index does not bear. Accordingly, the Fund’s performance will likely fail to match the performance of the Index, after taking expenses into account. Any of these factors could decrease correlation between the performance of the Fund and the Index and may hinder the Fund’s ability to meet its investment objective. It is not possible to invest directly in an index.

40	Prospectus 2019

Beta Advantage ^® ETFs

More Information About Columbia Sustainable U.S. Equity Income ETF (continued)

Early Close/Late Close/Trading Halt Risk.  An exchange or market may close early, close late or issue trading halts on specific securities, or the ability to buy or sell certain securities may be restricted, which may result in the Fund being unable to buy or sell these securities. In these circumstances, the Fund may be unable to rebalance its portfolio, may be unable to accurately price its investments, may incur substantial trading losses and/or may be prevented from sufficiently tracking the performance of the Index.

Environmental, Social and Governance Investing Risk . The Index’s environmental, social and corporate governance screening may cause the Fund to forgo certain investment opportunities, and/or forgo opportunities to gain exposure to certain industries, sectors, regions, countries and companies that could have benefited the Fund. In addition, the Fund may be required to sell a security when it might otherwise be disadvantageous for it to do so.

Fund Shares Liquidity Risk. Although the Fund’s shares are listed on the Exchange, there can be no assurance that an active, liquid or otherwise orderly trading market for shares will be established or maintained by market makers or Authorized Participants, particularly in times of stressed market conditions. In this regard, there is no obligation for market makers to make a market in the Fund’s shares or for Authorized Participants to submit purchase or redemption orders for creation units. Accordingly, if such parties determine not to perform their respective roles, this could, in turn, lead to variances between the market price of the Fund’s shares and the underlying value of those shares. Trading in Fund shares on the Exchange also may be disrupted or even halted due to market conditions or for reasons that, in the view of the Exchange, make trading in Fund shares inadvisable. In addition, trading in Fund shares on the Exchange may be subject to trading halts caused by extraordinary market volatility pursuant to the Exchange “circuit breaker” rules. There also can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund’s shares will continue to be met or will remain unchanged.

Index Methodology Risk. The Fund seeks performance that corresponds to the performance of the Index. There is no guarantee or assurance that the Index will achieve high, or even positive, returns. The Index may underperform more traditional indices. The Fund could lose value while other indices or measures of market performance increase in value or performance. In addition, the Fund may be subject to the risk that the index provider may not follow its stated methodology for construction of the Index and/or achieve the index provider’s intended performance objective. Errors may result in a negative performance impact to the Fund and its shareholders.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors. The market capitalization of an issuer may also impact its risk profile. Investments in larger, more established companies may involve certain risks associated with their larger size. For instance, larger, more established companies may be less able to respond quickly to new competitive challenges, such as changes in consumer tastes or innovation from smaller competitors. Also, larger companies are sometimes less able to attain the high growth rates of successful smaller companies, especially during extended periods of economic expansion.

Limitations of Intraday Indicative Value (IIV) Risk. The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the business day, (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close, which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. For example, if the Fund fair values portfolio securities, the Fund’s NAV may deviate from the approximate per share value of the Fund’s published basket of portfolio securities (i.e., the IIV), which could result in the market prices for Fund shares deviating from NAV. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Prospectus 2019

41

Beta Advantage ^® ETFs

More Information About Columbia Sustainable U.S. Equity Income ETF (continued)

Market Price Relative to NAV Risk. Shares of the Fund may trade at prices that vary from Fund NAV. Shares of the Fund are listed for trading on the Exchange and are bought and sold in the secondary market at market prices that may differ, in some cases significantly, from their NAV. The NAV of the Fund will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of shares, however, will generally fluctuate in response to changes in NAV, as well as the relative supply of, and demand for, Fund shares on the Exchange. The Investment Manager cannot predict whether Fund shares will trade below, at or above their NAV. Price differences may result because of, among other factors, supply and demand forces in the secondary trading market for Fund shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings. In this connection, if a shareholder purchases Fund shares at a time when the market price is at a premium to the NAV or sells shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses. Different investment strategies or techniques, including those intended to be defensive in nature, including, as examples, stop loss orders to sell an ETF’s shares in the secondary market during negative market events or conditions, such as a “flash crash” or other market disruptions may not work as intended and may produce significant losses to investors. Investors should consult their financial intermediary prior to using any such investment strategies or techniques, or before investing in the Fund.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. The value of Fund investments may fall or fail to rise because of a variety of actual or perceived factors affecting an issuer (e.g., unfavorable news), the industry or sector in which it operates, or the market as a whole, which may reduce the value of an investment in the Fund. Accordingly, an investment in the Fund could lose money over short or long periods. The market values of the investments the Fund holds can be affected by changes or potential or perceived changes in U.S. or foreign economies, financial markets, interest rates and the liquidity of these investments, among other factors.

Mid-Cap Company Securities Risk. Securities of mid-capitalization companies (mid-cap companies) can, in certain circumstances, have more risk than securities of larger capitalization companies (larger companies). For example, mid-cap companies may be more vulnerable to market downturns and adverse business or economic events than larger companies because they may have more limited financial resources and business operations. Mid-cap companies are also more likely than larger companies to have more limited product lines and operating histories and to depend on smaller and generally less experienced management teams. Securities of mid-cap companies may trade less frequently and in smaller volumes and may fluctuate more sharply in value than securities of larger companies. When the Fund takes significant positions in mid-cap companies with limited trading volumes, the liquidation of those positions, particularly in a distressed market, could be difficult and result in Fund investment losses that would affect the value of your investment in the Fund. In addition, some mid-cap companies may not be widely followed by the investment community, which can lower the demand for their stocks.

Passive Investment Risk. The Fund is not “actively” managed and may be affected by a general decline in market segments related to its underlying index. The Fund invests in securities or instruments included in, or believed by the Investment Manager to be representative of, its underlying index, regardless of their investment merits. The Fund does not seek temporary defensive positions when markets decline or appear overvalued. The decision of whether to remove a security from the Index is made by an independent index provider who is not affiliated with the Fund or the Investment Manager.

Secondary Market Trading Risk. Investors buying or selling Fund shares will pay brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of shares. In addition, secondary market investors will also incur the cost of the difference between the price that an investor is willing to pay for Fund shares (the bid price) and the price at which an investor is willing to sell Fund shares (the ask price). This difference in bid and ask prices is often referred to as the “spread” or “bid/ask spread.” The bid/ask spread varies over time for Fund shares based on trading volume and market liquidity, and is generally lower if the Fund’s shares have more trading volume and market liquidity and higher if the Fund’s shares have little trading volume and market liquidity. Further, increased market volatility may cause increased bid/ask spreads.

42	Prospectus 2019

Beta Advantage ^® ETFs

More Information About the Funds

References to “the Fund” throughout the remainder of the prospectus refer to the Funds singularly or collectively as the context requires.

How the Fund Differs from Traditional Mutual Funds

Redeemability. Traditional mutual fund shares may be bought from, and redeemed with, the issuing fund for cash at NAV typically calculated once at the end of each business day. Shares of the Fund, by contrast, cannot be purchased from or redeemed with the Fund except by or through Authorized Participants (defined below), and then typically for an in-kind basket of securities. In addition, the Fund issues and redeems shares on a continuous basis only in large blocks of shares, typically 50,000 shares, called Creation Units.

As an ETF, the Fund intends to rely on an exemptive order issued by the SEC to the Trust that permits the Fund to delay payment of redemption proceeds for its securities for up to 14 calendar days, based in part on the greater relative illiquidity and longer settlement times of emerging market securities. This risk applies to investors such as market makers, large investors and institutions who purchase and sell Creation Units directly from and to the Fund and does not apply to investors who will buy and sell shares of the Fund in secondary market transactions on the Exchange through brokers.

Exchange Listing. Unlike traditional mutual fund shares, the Fund’s shares are listed for trading on the Exchange. Investors can purchase and sell shares on the secondary market through a broker or other financial intermediary (collectively, financial intermediary(ies)). There can be no assurance that the Fund's shares will continue to trade on the Exchange or that the Fund's shares will continue to meet the requirements for listing or trading on the Exchange. See "Fund Shares Liquidity Risk" above. Investors purchasing shares in the secondary market through a brokerage account or with the assistance of a financial intermediary may be subject to brokerage commissions and charges. Secondary-market transactions do not occur at NAV, but at market prices that change throughout the day, based on the supply of, and demand for, shares and on changes in the prices of the Fund’s portfolio holdings. The market price of shares may differ from the NAV of the Fund. The difference between market price of shares and the NAV of the Fund is called a premium when the market price is above the reported NAV and called a discount when the market price is below the reported NAV. The market price of the Fund's shares may deviate significantly from the NAV of the shares, for example, in times of extreme market volatility or other conditions.

Tax Treatment. The Fund’s structure may provide for enhanced tax efficiency relative to a traditional mutual fund’s structure. Specifically, to the extent the Fund redeems its shares in kind, the distribution of portfolio securities to meet such redemption requests may mitigate certain adverse tax consequences associated with traditional mutual fund shares to continuing Fund shareholders. This is because traditional mutual funds typically sell portfolio securities to obtain cash to meet redemptions and, as necessary, may recognize taxable gains in connection with such sales. By contrast, to the extent the Fund redeems its shares in kind, as opposed to in cash, the Fund’s in-kind redemption mechanism will potentially reduce, relative to a traditional mutual fund, taxable gains resulting from redemptions. However, the Fund cannot predict to what extent, if any, it will redeem its shares in kind rather than in cash, particularly during the Fund’s growth stages when portfolio changes are more likely to be implemented within the Fund rather than through the in-kind redemption mechanism. Nor can the Fund predict the extent to which any such in-kind redemptions will reduce the taxable gain recognized in connection therewith.

ETFs generally are able to make in-kind redemptions and avoid being taxed on gain on the distributed portfolio securities at the Fund level. Because the Fund may effect redemptions partly or entirely in cash, rather than in-kind distributions, it may be required to sell portfolio securities in order to obtain the cash needed to distribute redemption proceeds. If the Fund recognizes gain on these sales, this generally will cause the Fund to recognize gain it might not otherwise have recognized, or to recognize such gain sooner than would otherwise be required if it were to distribute portfolio securities in-kind. The Fund generally intends to distribute these gains to shareholders to avoid being taxed on this gain at the Fund level and otherwise comply with the special tax rules that apply to it. This strategy may cause shareholders to be subject to tax on gains they would not otherwise be subject to, or at an earlier date than, if they had made an investment in a different ETF. Moreover, cash transactions may have to be carried out

Prospectus 2019

43

Beta Advantage ^® ETFs

More Information About the Funds (continued)

over several days if the securities market is relatively illiquid and may involve considerable brokerage fees and taxes. These brokerage fees and taxes, which will be higher than if the Fund sold and redeemed its shares principally in-kind, will be passed on to purchasers and redeemers of Creation Units in the form of creation and redemption transaction fees.

Additional Investment Strategies and Policies

This section describes certain investment strategies and policies that the Fund may utilize in pursuit of its investment objective and some additional factors and risks involved with investing in the Fund.

The Fund may consider changing the Index at any time, including if, for example: the Index becomes unavailable; the Board believes that the Index no longer serves shareholder investment needs or that another index may better serve their needs; or the financial or economic environment makes it difficult for the Fund’s investment results to correspond sufficiently to the Index. If the Fund determines to change the Index, it will assess the appropriateness of the Fund's current name in light of the new index.

20% Asset Policy

In addition to any instruments mentioned in the Fund’s principal investment strategies, the Fund may invest up to 20% of its net assets in derivatives, including forward contracts (including forward foreign currency contracts), futures (including equity futures and index futures), options (including options on futures) and swaps (including portfolio and total return swaps), as well as cash, cash equivalents and money market instruments, such as repurchase agreements and money market funds (including affiliated money market funds), for the purpose of seeking to assist the Fund in tracking the performance of the Index.

Investment Guidelines

As a general matter, and except as specifically described in the discussion of the Fund's principal investment strategies in this prospectus or as otherwise required by the Investment Company Act of 1940, as amended (the 1940 Act), the rules and regulations thereunder and any applicable exemptive relief, whenever an investment policy or limitation states a percentage of the Fund's assets that may be invested in any security or other asset or sets forth a policy regarding an investment standard, compliance with that percentage limitation or standard will be determined solely at the time of the Fund's investment in the security or asset.

Holding Other Kinds of Investments

The Fund may hold other investments that are not part of its principal investment strategies. These investments and their risks are described below and/or in the SAI. The Fund may choose not to invest in certain securities described in this prospectus and in the SAI, although it has the ability to do so. Information on the Fund’s holdings can be found in the Fund’s shareholder reports or by visiting columbiathreadneedleetf.com.

Transactions in Derivatives

The Fund may enter into derivative transactions. Derivatives are financial contracts whose values are, for example, based on (or “derived” from) traditional securities (such as a stock or bond), assets (such as a commodity like gold or a foreign currency), reference rates (such as the London Interbank Offered Rate (commonly known as LIBOR)) or market indices (such as the Standard & Poor's (S&P) 500 ^® Index). The use of derivatives is a highly specialized activity which involves investment techniques and risks different from those associated with ordinary portfolio securities transactions. Derivatives involve special risks and may result in losses or may limit the Fund's potential gain from favorable market movements. Derivative strategies often involve leverage, which may exaggerate a loss, potentially causing the Fund to lose more money than it would have lost had it invested in the underlying security or other asset directly. The values of derivatives may move in unexpected ways, especially in unusual market conditions, and may result in increased volatility in the value of the derivative and/or the Fund’s shares, among other consequences. The use of derivatives may also increase the amount of taxes payable by shareholders holding shares in a taxable account. Other risks arise from the Fund's potential inability to terminate or to sell derivative positions. A liquid secondary market may not always exist for the Fund's derivative positions at times when the Fund might wish to terminate or to sell such positions. Over-the-counter instruments (investments not traded on an exchange) may be

44	Prospectus 2019

Beta Advantage ^® ETFs

More Information About the Funds (continued)

illiquid, and transactions in derivatives traded in the over-the-counter market are subject to the risk that the other party will not meet its obligations. The use of derivatives also involves the risks of mispricing or improper valuation and that changes in the value of the derivative may not correlate perfectly with the underlying security, asset, reference rate or index. The Fund also may not be able to find a suitable derivative transaction counterparty, and thus may be unable to engage in derivative transactions when it is deemed favorable to do so, or at all. U.S. federal legislation has been enacted that provides for new clearing, margin, reporting and registration requirements for participants in the derivatives market. These changes could restrict and/or impose significant costs or other burdens upon the Fund’s participation in derivatives transactions. For more information on the risks of derivative investments and strategies, see the SAI.

Affiliated Funds Investing in the Fund

The Investment Manager or an affiliate serves as investment adviser to funds using the Columbia brand (Columbia Funds), including those that are structured as “fund-of-funds”, and provides asset-allocation services to (i) shareholders by investing in shares of other Columbia Funds, which may include the Fund (collectively referred to in this section as Underlying Funds), and (ii) discretionary managed accounts (collectively referred to as affiliated products) that invest exclusively in Underlying Funds. These affiliated products, individually or collectively, may own a significant percentage of the outstanding shares of one or more Underlying Funds, and the Investment Manager seeks to balance potential conflicts of interest between the affiliated products and the Underlying Funds in which they invest. The affiliated products’ investment in the Underlying Funds may have the effect of creating economies of scale, possibly resulting in lower expense ratios for the Underlying Funds, because the affiliated products may own substantial portions of the shares of Underlying Funds. However, redemption of Underlying Fund shares by one or more affiliated products could cause the expense ratio of an Underlying Fund to increase, as its fixed costs would be spread over a smaller asset base. Because of large positions of certain affiliated products, the Underlying Funds may experience relatively large inflows and outflows of cash due to affiliated products’ purchases and sales of Underlying Fund shares. Although the Investment Manager or its affiliate may seek to minimize the impact of these transactions where possible, for example, by structuring them over a reasonable period of time or through other measures, Underlying Funds may experience increased expenses as they buy and sell portfolio securities to manage the cash flow effect related to these transactions. Further, when the Investment Manager or its affiliate structures transactions over a reasonable period of time in order to manage the potential impact of the buy and sell decisions for the affiliated products, those affiliated products, including funds-of-funds, may pay more or less (for purchase activity), or receive more or less (for redemption activity), for shares of the Underlying Funds than if the transactions were executed in one transaction. In addition, substantial redemptions by affiliated products within a short period of time could require the Underlying Fund to liquidate positions more rapidly than would otherwise be desirable, which may have the effect of reducing or eliminating potential gain or causing it to realize a loss. In order to meet such redemptions, an Underlying Fund may be forced to sell its liquid (or more liquid) positions, leaving the Underlying Fund holding, post-redemption, a relatively larger position in illiquid investments (i.e., any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment) or less liquid securities. Substantial redemptions may also adversely affect the ability of the Underlying Fund to implement its investment strategy. The Investment Manager or its affiliate also has a conflict of interest in determining the allocation of affiliated products’ assets among the Underlying Funds, as it earns different fees from the various Underlying Funds.

Investing in Money Market Funds

The Fund may invest cash in, or hold as collateral for certain investments, shares of registered or unregistered money market funds, including funds advised by the Investment Manager or its affiliates. These funds are not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. The Fund and its shareholders indirectly bear a portion of the expenses of any money market fund or other fund in which the Fund may invest.

Prospectus 2019

45

Beta Advantage ^® ETFs

More Information About the Funds (continued)

Fund Website and Disclosure of Portfolio Holdings

Information about the Fund may be found at columbiathreadneedleetf.com. Among other things, this website includes the Summary Prospectus, this prospectus and the SAI, the Fund’s holdings, the Fund’s last annual and semiannual reports, pricing information about shares trading on the Exchange, daily NAV calculations and a historical comparison of the trading prices to NAV.

Each day the Fund is open for business, it publicly disseminates the Fund’s full portfolio holdings as of the close of the previous business day through its website at columbiathreadneedleetf.com. In addition, the In-Kind Creation Basket and In-Kind Redemption Basket, which identify the securities and share quantities which may be delivered in exchange for purchases and redemptions of Creation Units as discussed below and in the SAI, are publicly disseminated each business day prior to the opening of trading on the Exchange via the National Securities Clearing Corporation (NSCC).

Additional Information on Portfolio Turnover

A fund that replaces, or turns over, more than 100% of its investments in a year may be considered to have a high portfolio turnover rate. A high portfolio turnover rate can generate larger distributions of short-term capital gains to shareholders, which for individuals are generally taxable at higher rates than long-term capital gains for U.S. federal income tax purposes. Also, a high portfolio turnover rate can mean higher brokerage commissions and other transaction costs, which could reduce a fund’s returns. In general, the greater the volume of buying and selling by a fund, the greater the impact that brokerage commissions and other transaction costs will have on its returns. The Fund may sell securities regardless of how long they’ve been held. A higher portfolio turnover rate may reduce the relative potential tax efficiency of the Fund compared with traditional mutual funds except potentially in cases where accomplished through redemptions in kind. You'll find the Fund's portfolio turnover rate for its most recent fiscal period in the Fees and Expenses of the Fund — Portfolio Turnover section of this prospectus and portfolio turnover rates for the past five years or since inception, if the Fund has been in operation for less than five years, in the Financial Highlights section of this prospectus.

Understanding Annual Fund Operating Expenses

The Fund’s annual operating expenses, as presented in the Annual Fund Operating Expenses table in the Fees and Expenses of the Fund section of this prospectus, generally are based on expenses incurred during the Fund’s most recently completed fiscal year and are expressed as a percentage (expense ratio) of the Fund’s average net assets during that fiscal year. The expense ratio reflects the Fund’s fee arrangements as of the date of this prospectus and, unless indicated otherwise, is based on expenses incurred during the Fund’s most recent fiscal year. The Fund’s assets will fluctuate, but unless indicated otherwise in the Annual Fund Operating Expenses table, no adjustments have been or will be made to the expense ratio to reflect any differences in the Fund’s average net assets between the most recently completed fiscal year and the date of this prospectus or a later date. As applicable, any commitment by the Investment Manager and/or its affiliates to waive fees and/or cap (reimburse) expenses is expected, in part, to limit the impact of any increase in the Fund’s expense ratio that would otherwise result because of a decrease in the Fund’s assets in the current fiscal year. The Fund’s annual operating expenses are comprised of (i) investment management fees, (ii) distribution and/or service fees, and (iii) other expenses.

Primary Service Providers

The Fund enters into contractual arrangements (Service Provider Contracts) with various service providers, including, among others, the Investment Manager, the administrator, the distributor, the transfer agent and the Fund’s custodian. The Fund’s Service Provider Contracts are solely among the parties thereto. Shareholders are not parties to, or intended to be third-party beneficiaries of, any Service Provider Contracts. Further, this prospectus, the SAI and any Service Provider Contracts are not intended to give rise to any agreement, duty, special relationship or other obligation between the Fund and any investor, or give rise to any contractual, tort or other rights in any individual shareholder, group of shareholders or other person, including any right to assert a fiduciary or other duty, enforce the Service Provider Contracts against the parties or to seek any remedy thereunder, either directly or on behalf of the Fund. Nothing in the previous sentence should be read to suggest any waiver of any rights under federal or state securities laws.

46	Prospectus 2019

Beta Advantage ^® ETFs

More Information About the Funds (continued)

Beta Advantage ^® ETFs

More Information About the Funds (continued)

Ameriprise Financial is a major financial services company, engaged in a broad range of financial activities beyond the fund-related activities of the Investment Manager, including, among others, insurance, broker-dealer (sales and trading), asset management, banking and other financial activities. These additional activities may involve multiple advisory, financial, insurance and other interests in securities and other instruments, and in companies that issue securities and other instruments, that may be bought, sold or held by the Columbia Funds.

Conflicts of interest and limitations that could affect a Columbia Fund may arise from, for example, the following:

■	compensation and other benefits received by the Investment Manager and other Ameriprise Financial affiliates related to the management/administration of a Columbia Fund and the sale of its shares;

■	the allocation of, and competition for, investment opportunities among the Fund, other funds and accounts advised/managed by the Investment Manager and other Ameriprise Financial affiliates, or Ameriprise Financial itself and its affiliates;

■	separate and potentially divergent management of a Columbia Fund and other funds and accounts advised/managed by the Investment Manager and other Ameriprise Financial affiliates;

■	regulatory and other investment restrictions on investment activities of the Investment Manager and other Ameriprise Financial affiliates and accounts advised/managed by them;

■	insurance and other relationships of Ameriprise Financial affiliates with companies and other entities in which a Columbia Fund invests; and

■	regulatory and other restrictions relating to the sharing of information between Ameriprise Financial and its affiliates, including the Investment Manager, and a Columbia Fund.

The Investment Manager and Ameriprise Financial have adopted various policies and procedures that are intended to identify, monitor and address conflicts of interest. However, there is no assurance that these policies, procedures and disclosures will be effective.

Additional information about Ameriprise Financial and the types of conflicts of interest and other matters referenced above is set forth in the Investment Management and Other Services — Other Roles and Relationships of Ameriprise Financial and its Affiliates — Certain Conflicts of Interest section of the SAI. Investors in the Columbia Funds should carefully review these disclosures and consult with their financial advisor if they have any questions.

Certain Legal Matters

Ameriprise Financial and certain of its affiliates have historically been involved in a number of legal, arbitration and regulatory proceedings, including routine litigation, class actions and governmental actions, concerning matters arising in connection with the conduct of their business activities. Ameriprise Financial believes that the Fund is not currently the subject of, and that neither Ameriprise Financial nor any of its affiliates are the subject of, any pending legal, arbitration or regulatory proceedings that are likely to have a material adverse effect on the Fund or the ability of Ameriprise Financial or its affiliates to perform under their contracts with the Fund. Information regarding certain pending and settled legal proceedings may be found in the Fund’s shareholder reports and in the SAI. Additionally, Ameriprise Financial is required to make quarterly (10-Q), annual (10-K) and, as necessary, 8-K filings with the SEC on legal and regulatory matters that relate to Ameriprise Financial and its affiliates. Copies of these filings may be obtained by accessing the SEC website at sec.gov.

Prospectus 2019

49

Beta Advantage ^® ETFs

Beta Advantage ^® ETFs

Buying and Selling Fund Shares (continued)

confirmations of your purchases and sales of shares, and tax information. Your financial intermediary also will be responsible for distributing income dividends and capital gain distributions and for ensuring that you receive shareholder reports and other communications from the Fund.

Share Trading Prices. The trading prices of the Fund’s shares may differ from the Fund’s daily NAV and can be affected by market forces of supply and demand for the Fund’s shares, the prices of the Fund’s investments, economic conditions and other factors. The Exchange or another market information provider intends to disseminate the approximate value of the Fund’s portfolio every fifteen seconds. This approximate value should not be viewed as a “real-time” update of the NAV of the Fund because the approximate value may not be calculated in the same manner as the NAV, which is computed once a day. The quotations for certain investments may not be updated during U.S. trading hours if such holdings do not trade in the U.S., except such quotations may be updated to reflect currency fluctuations. The Fund is not involved in, or responsible for, the calculation or dissemination of the approximate values and makes no warranty as to the accuracy of these values.

Buying Fund Shares Directly from the Fund

Fund shares can only be purchased directly from the Fund by an Authorized Participant or through an Authorized Participant. An “Authorized Participant” is a participant of the Continuous Net Settlement System of the NSCC or the DTC that has executed a Participant Agreement with the Distributor, and accepted by the Transfer Agent. The Distributor will provide a list of Authorized Participants upon request. Authorized Participants may purchase Creation Units of shares, and sell individual shares on the Exchange. See Continuous Offering below.

An Authorized Participant can purchase Fund shares directly from the Fund only in Creation Units or multiples thereof. The number of shares in a Creation Unit may, but is not expected to, change over time. The Fund will not issue fractional Creation Units. Creation Units may be purchased in exchange for a basket of securities or other portfolio instruments (known as the In-Kind Creation Basket and a Cash Component ) or for an all cash payment (that would be treated as the Cash Component (discussed below) in connection with purchases not involving an In-Kind Creation Basket ). The Fund reserves the right to reject any purchase request at any time, for any reason, and without notice.

In-Kind Creation Basket. On each business day, prior to the opening of trading on the Exchange, BNY Mellon will post on the NSCC bulletin board the In-Kind Creation Basket for the Fund for that day. The In-Kind Creation Basket will identify the name and number of shares of each security or other instrument that must be contributed to the Fund for each Creation Unit purchased. The Fund reserves the right to accept a nonconforming or “custom” In-Kind Creation Basket under certain limited circumstances. In the case of custom orders, the order must be received by the Distributor no later than 3:00 p.m. ET.

Balancing Amount and Cash Component. In addition to the In-Kind Creation Basket, a purchaser will either pay to, or receive from, the Fund an amount of cash (“Balancing Amount”) equal to the difference between the NAV of a Creation Unit and the value of the securities in the In-Kind Creation Basket. The Balancing Amount ensures that the consideration paid by an investor for a Creation Unit is exactly equal to the value of the Creation Unit. BNY Mellon will publish, on a daily basis, information about the previous business day’s Balancing Amount. To the extent a purchaser is not owed a Balancing Amount larger than the Creation Transaction Fee, described below, the purchaser also must pay a Creation Transaction Fee, in cash. The Balancing Amount and the Creation Transaction Fee, taken together, are referred to as the Cash Component.

Placement of Purchase Orders. All purchase orders must be placed by or through an Authorized Participant. Purchase orders will be processed either through a manual clearing process run by DTC or through an enhanced clearing process that is available only to those DTC participants that also are participants in the Continuous Net Settlement System of the NSCC. Authorized Participants that do not use the NSCC’s enhanced clearing process may be charged a higher Creation Transaction Fee (discussed below). A purchase order must be received by the Distributor prior to the end of the business day (generally 4:00 p.m., Eastern time) on the day the order is placed, and all other procedures set forth in the Participant Agreement must be followed, in order to receive the NAV determined on that day.

Prospectus 2019

51

Beta Advantage ^® ETFs

Buying and Selling Fund Shares (continued)

Transaction Fee on Purchases of Creation Units. The Fund may impose a “Creation Transaction Fee” on each purchase of Creation Units. The Creation Transaction Fee for purchases effected through the NSCC’s enhanced clearing process, regardless of the number of Creation Units purchased, is $2,000 for Columbia Sustainable Global Equity Income ETF and Columbia Sustainable International Equity Income ETF and $500 for Columbia Sustainable U.S. Equity Income ETF. The Creation Transaction Fee is paid to the Funds. The fee is designed to protect existing shareholders of the Funds from the costs associated with issuing Creation Units.

A higher Creation Transaction Fee noted above may be imposed on purchases outside the NSCC’s enhanced clearing process, including purchases involving nonconforming In-Kind Creation Baskets or cash. Investors who, directly or indirectly, use the services of a broker or other such intermediary to compile the securities or other instruments in the In-Kind Creation Basket may pay additional fees for these services.

Redeeming Fund Shares Directly from the Fund

Fund shares can only be redeemed directly with the Fund by an Authorized Participant or through an Authorized Participant. An Authorized Participant may redeem Fund shares directly from the Fund only in Creation Units or multiples thereof. Creation Units may be redeemed in exchange for a basket of securities or other instruments (known as the In-Kind Redemption Basket and a Cash Component ) or, in certain circumstances, for all cash payment (that would be treated as the Cash Component (discussed below) in connection with purchases not involving an In-Kind Redemption Basket ). The Fund can suspend redemptions or postpone payment of redemption proceeds for any period during which: (1) the New York Stock Exchange (NYSE) is closed other than customary weekend and holiday closings; (2) trading on the NYSE is suspended or restricted; (3) an emergency exists as a result of which disposal of the Shares or determination of the Fund’s NAV is not reasonably practicable or it is not reasonably practicable for the Fund to fairly determine the value of its net assets; and (4) the SEC by order permits for the protection of shareholders of a Fund. The Fund may also postpone payment of redemption proceeds for up to 15 calendar days due to holdings in non-U.S. investments, as further described in the SAI.

In-Kind Redemption Basket. Redemption proceeds will generally be paid in kind with a basket of securities or other portfolio instruments known as the In-Kind Redemption Basket. In most cases, the In-Kind Redemption Basket will be the same as the In-Kind Creation Basket for that same day. There will be times, however, when the In-Kind Creation Basket and In-Kind Redemption Baskets differ. The composition of the In-Kind Redemption Basket will be available on the NSCC bulletin board each day the NYSE is open for business. The Fund may honor a redemption request with a nonconforming or “custom” In-Kind Redemption Basket under certain limited circumstances.

Balancing Amount and Cash Component. Depending on whether the NAV of a Creation Unit is higher or lower than the value of the securities or other portfolio instruments in the In-Kind Redemption Basket, a redeeming investor will either receive from, or pay to, the Fund a Balancing Amount in cash. If due to receive a Balancing Amount, the amount actually received will be reduced by the amount of the applicable Redemption Transaction Fee, described below. The Balancing Amount and the Redemption Transaction Fee, taken together, are referred to as the Cash Component.

Placement of Redemption Orders. As with purchases, redemptions must be processed either through the DTC process or the enhanced NSCC process. A redemption order is deemed received on the date of transmittal if it is received by the Distributor prior to the end of the business day on that date, and if all other procedures set forth in the Participant Agreement are followed.

Transaction Fee on Redemptions of Creation Units. The Fund imposes a “Redemption Transaction Fee” on each redemption of Creation Units. The amount of the Redemption Transaction Fee on redemptions effected through the NSCC and DTC, and on nonconforming or "custom" redemptions, is the same as the Creation Transaction Fee. The Redemption Transaction fee is paid to the Fund. The fee is designed to protect existing shareholders of the Fund from the costs associated with redeeming Creation Units.

52	Prospectus 2019

Beta Advantage ^® ETFs

Buying and Selling Fund Shares (continued)

Additional Information About Buying and Selling Fund Shares

Legal Restrictions on Transactions in Certain Securities. An investor subject to a legal restriction with respect to a particular security required to be deposited in connection with the purchase of a Creation Unit may, at the Fund’s discretion, be permitted to deposit an equivalent amount of cash in substitution for any security which would otherwise be included in the In-Kind Creation Basket applicable to the purchase of a Creation Unit.

Creations and redemptions of shares will be subject to applicable federal and state securities laws, including that securities accepted for deposit and securities used to satisfy redemption requests are sold in transactions that would be exempt from registration under the Securities Act of 1933, as amended (the Securities Act). The Fund (whether or not it otherwise permits cash redemptions) reserves the right to redeem Creation Units for cash to the extent that an investor could not lawfully purchase or the Fund could not lawfully deliver specific securities under such laws or the local laws of a jurisdiction in which the Fund invests. An Authorized Participant or an investor for which it is acting subject to a legal restriction with respect to a particular security included in an In-Kind Redemption Basket may be paid an equivalent amount of cash. An Authorized Participant or redeeming investor for which it is acting that is not a qualified institutional buyer (QIB) as defined in Rule 144A under the Securities Act will not be able to receive, as part of a redemption, restricted securities eligible for resale under Rule 144A.

Continuous Offering. Authorized Participants should be aware of certain legal risks unique to investors purchasing Creation Units directly from the Fund. Because shares may be issued on an ongoing basis, a “distribution” of shares could be occurring at any time. Certain activities that Authorized Participants perform with respect to the sale of shares could, depending on the circumstances, result in Authorized Participants being deemed to be a participant in the distribution, in a manner that could render Authorized Participants a statutory underwriter and subject Authorized Participants to the prospectus delivery and liability provisions of the Securities Act. For example, Authorized Participants could be deemed a statutory underwriter if Authorized Participants purchase Creation Units from the issuing Fund, break them down into the constituent shares, and sell those shares directly to customers, or if Authorized Participants choose to couple the creation of a supply of new shares with an active selling effort involving solicitation of secondary market demand for shares. Whether a person is an underwriter for purposes of the Securities Act depends upon all of the facts and circumstances pertaining to that person’s activities, and the examples mentioned here should not be considered a complete description of all the activities that could cause Authorized Participants to be deemed an underwriter.

Broker-dealer firms should also note that dealers who are not “underwriters” but are effecting transactions in shares, whether or not participating in the distribution of shares, are generally required to deliver a prospectus. This is because the prospectus delivery exemption in Section 4(3) of the Securities Act is not available in respect of such transactions as a result of Section 24(d) of the 1940 Act. As a result, broker-dealer firms should note that dealers who are not “underwriters” but are participating in a distribution (as opposed to engaging in ordinary secondary market transactions), and thus dealing with shares as part of an unsold allotment within the meaning of Section 4(3)(C) of the Securities Act, will be unable to take advantage of the prospectus delivery exemption provided by Section 4(3) of the Securities Act. For delivery of prospectuses to exchange members, the prospectus delivery mechanism of Rule 153 under the Securities Act is only available with respect to transactions on a national exchange.

Active Investors and Market Timing

The Board has determined not to adopt policies and procedures designed to prevent or monitor for frequent purchases and redemptions of the Fund’s shares because investors primarily transact in Fund shares on the secondary market. Frequent trading of shares on the secondary market does not disrupt portfolio management, increase the Fund’s trading costs, lead to realization of capital gains or otherwise harm Fund shareholders because these trades do not involve the issuance or redemption of Fund shares.

The Fund sells and redeems its shares at NAV only in Creation Units pursuant to the terms of a Participant Agreement between an Authorized Participant and the Distributor, principally in exchange for a basket of securities. With respect to such trades directly with the Fund to the extent effected in-kind (i.e., for securities), they generally would not cause the harmful effects that may result from frequent cash trades.

Prospectus 2019

53

Beta Advantage ^® ETFs

Buying and Selling Fund Shares (continued)

The Board recognizes that to the extent that the Fund allows or requires trades to be effected in whole or in part in cash, those trades could result in dilution to a Fund and increased transaction costs, which could negatively impact the Fund’s ability to achieve its investment objective. The Board also recognizes, however, that direct trading by Authorized Participants is critical to ensuring that the Fund’s shares trade at or close to NAV. Further, the Fund may employ fair valuation pricing to minimize the potential for dilution from market timing. Moreover, the Fund imposes transaction fees on purchases and redemptions of Fund shares reflecting the fact that the Fund’s costs increase in those circumstances. The Fund reserves the right to impose additional restrictions on disruptive, excessive or short-term purchases.

Distribution and Service Fees

The Board has approved, and the Fund has adopted, a distribution and service plan (the Plan) pursuant to Rule 12b-1 under the 1940 Act. Under the Plan, the Fund is authorized to pay distribution fees to the Distributor and other firms that provide distribution and shareholder services (Service Providers). If a Service Provider provides such services, the Fund may pay fees at an annual rate not to exceed 0.25% of average daily net assets, pursuant to Rule 12b-1 under the 1940 Act.

No distribution or service fees are currently paid by the Fund, however, and there are no current plans to impose these fees. Future payments may be made under the Plan without any further shareholder approval. In the event Rule 12b-1 fees are charged, over time they would increase the cost of an investment in the Fund.

Intraday Indicative Value (IIV)

The Exchange intends to disseminate the approximate per share value of the Fund’s published basket of portfolio securities every 15 seconds (the ‘‘intraday indicative value’’ or ‘‘IIV’’). The IIV should not be viewed as a ‘‘real-time’’ update of the NAV per share of the Fund because (i) the IIV may not be calculated in the same manner as the NAV, which is computed once a day, generally at the end of the Business Day (as defined below), (ii) the calculation of NAV may be subject to fair valuation at different prices than those used in the calculations of the IIV, (iii) unlike the calculation of NAV, the IIV does not take into account Fund expenses, and (iv) the IIV is based on the published basket of portfolio securities and not on the Fund’s actual holdings. The IIV calculations are based on local market prices and may not reflect events that occur subsequent to the local market’s close (except such quotations may be updated to reflect currency fluctuations), which could affect premiums and discounts between the IIV and the market price of the Fund’s shares. The Fund, the Investment Manager and their affiliates are not involved in, or responsible for, any aspect of the calculation or dissemination of the Fund’s IIV, and the Fund, the Investment Manager and their affiliates do not make any warranty as to the accuracy of these calculations.

Determination of Net Asset Value

54	Prospectus 2019

Beta Advantage ^® ETFs

Buying and Selling Fund Shares (continued)

Equity securities are valued primarily on the basis of market quotations reported on stock exchanges and other securities markets around the world. If an equity security is listed on a national exchange, the security is valued at the closing price or, if the closing price is not readily available, the mean of the closing bid and asked prices. Certain equity securities, debt securities and other assets are valued differently. For instance, bank loans trading in the secondary market are valued primarily on the basis of indicative bids, fixed income investments maturing in 60 days or less are valued primarily using the amortized cost method, unless this methodology results in a valuation that does not approximate the market value of these securities, and those maturing in excess of 60 days are valued primarily using a market-based price obtained from a pricing service, if available. Investments in other open-end funds are valued at their published NAVs. Both market quotations and indicative bids are obtained from outside pricing services approved and monitored pursuant to a policy approved by the Fund's Board.

If a market price is not readily available or is deemed not to reflect market value, the Fund will determine the price of a portfolio security based on a determination of the security's fair value pursuant to a policy approved by the Fund's Board. In addition, the Fund may use fair valuation to price securities that trade on a foreign exchange when a significant event has occurred after the foreign exchange closes but before the time at which the Fund's share price is calculated. Foreign exchanges typically close before the time at which Fund share prices are calculated, and may be closed altogether on some days when the Fund is open. Such significant events affecting a foreign security may include, but are not limited to: (1) corporate actions, earnings announcements, litigation or other events impacting a single issuer; (2) governmental action that affects securities in one sector or country; (3) natural disasters or armed conflicts affecting a country or region; or (4) significant domestic or foreign market fluctuations. The Fund uses various criteria in determining whether a foreign security's market price is readily available and reflective of market value and, if not, the fair value of the security. To the extent the Fund has significant holdings of small cap stocks, high-yield bonds, floating rate loans, or tax-exempt, foreign or other securities that may trade infrequently, fair valuation may be used more frequently than for other funds.

Fair valuation may have the effect of reducing stale pricing arbitrage opportunities presented by the pricing of Fund shares. However, when the Fund uses fair valuation to price securities, it may value those securities higher or lower than another fund would have priced the security. Also, the use of fair valuation may cause the Fund's performance to diverge to a greater degree from the performance of various benchmarks used to compare the Fund's performance because benchmarks generally do not use fair valuation techniques. Because of the judgment involved in fair valuation decisions, there can be no assurance that the value ascribed to a particular security is accurate.

Prospectus 2019

55

Beta Advantage ^® ETFs

Beta Advantage ^® ETFs

Distributions and Taxes (continued)

Taxes

You should be aware of the following considerations applicable to the Funds:

■

The Fund intends to qualify and to be eligible for treatment each year as a regulated investment company. A regulated investment company generally is not subject to tax at the fund level on income and gains from investments that are distributed to shareholders. However, the Fund's failure to qualify for treatment as a regulated investment company would result in Fund-level taxation, and consequently, a reduction in income available for distribution to you and in the NAV of your shares. Even if the Fund qualifies for treatment as a regulated investment company, the Fund may be subject to federal excise tax on certain undistributed income or gains.

■

Otherwise taxable distributions generally are taxable to you when paid, whether they are paid in cash or automatically reinvested in additional Fund shares. Dividends paid in January are deemed paid on December 31 of the prior year if the dividend was declared and payable to shareholders of record in October, November, or December of such prior year.

■

Distributions of the Fund's ordinary income and net short-term capital gain, if any, generally are taxable to you as ordinary income. Distributions of the Fund's net long-term capital gain, if any, generally are taxable to you as long-term capital gain. Whether capital gains are long-term or short-term is determined by how long the Fund has owned the investments that generated them, rather than how long you have owned your shares.

■

From time to time, a distribution from the Fund could constitute a return of capital. A return of capital is a return of an amount of your original investment and is not a distribution of income or capital gain from the Fund. Therefore, a return of capital is not taxable to you so long as the amount of the distribution does not exceed your tax basis in your Fund shares. A return of capital reduces your tax basis in your Fund shares, with any amounts exceeding such basis generally taxable as capital gain.

■

If you are an individual and you meet certain holding period and other requirements for your Fund shares, a portion of your distributions may be treated as “qualified dividend income” taxable at the lower net long-term capital gain rates instead of the higher ordinary income rates. Qualified dividend income is income attributable to the Fund's dividends received from certain U.S. and foreign corporations, as long as the Fund meets certain holding period and other requirements for the stock producing such dividends.

■	Certain high-income individuals (as well as estates and trusts) are subject to a 3.8% tax on net investment income. For individuals, the 3.8% tax applies to the lesser of (1) the amount (if any) by which the taxpayer's modified adjusted gross income exceeds certain threshold amounts or (2) the taxpayer's “net investment income.”
	Net investment income generally includes for this purpose dividends, including any capital gain dividends, paid by the Fund, and net gains recognized on the sale, redemption or exchange of shares of the Fund.

■

Certain derivative instruments when held in the Fund's portfolio subject the Fund to special tax rules, the effect of which may be to, among other things, accelerate income to the Fund, defer Fund losses, cause adjustments in the holding periods of Fund portfolio securities, or convert capital gains into ordinary income, short-term capital losses into long-term capital losses or long-term capital gains into short-term capital gains. These rules could therefore affect the amount, timing and/or character of distributions to shareholders.

■

Generally, a Fund realizes a capital gain or loss on an option when the option expires, or when it is exercised, sold or otherwise terminated. However, if an option is a “section 1256 contract,” which includes most traded options on a broad-based index, and the Fund holds such option at the end of its taxable year, the Fund is deemed to sell such option at fair market value at such time and recognize any gain or loss thereon, which is generally deemed to be 60% long-term and 40% short-term capital gain or loss, as described further in the SAI.

■

Income and proceeds received by the Fund from sources within foreign countries may be subject to foreign taxes. If at the end of the taxable year more than 50% of the value of the Fund's assets consists of securities of foreign corporations, and the Fund makes a special election, you will generally be required to include in your income for U.S. federal income tax purposes your share of the qualifying foreign income taxes paid by the Fund in respect of

Prospectus 2019

57

Beta Advantage ^® ETFs

Distributions and Taxes (continued)

its foreign portfolio securities. You may be able to claim a foreign tax credit or deduction in respect of this amount, subject to certain limitations. There is no assurance that the Fund will make this election for a taxable year, even if it is eligible to do so.

■

A sale, redemption or exchange of Fund shares is a taxable event. This includes redemptions where you are paid in securities. Your sales, redemptions and exchanges of Fund shares, including those paid in securities or other instruments, usually will result in a taxable capital gain or loss to you, equal to the difference between the amount you receive for your shares (or are deemed to have received in the case of exchanges) and your adjusted tax basis in the shares, which is generally the amount you paid (or are deemed to have paid in the case of exchanges) for them. Any such capital gain or loss generally will be long-term capital gain or loss if you have held your Fund shares for more than one year at the time of sale or exchange. In certain circumstances, capital losses may be converted from short-term to long-term; in other circumstances, capital losses may be disallowed under the “wash sale” rules.

■

Your broker will be responsible for furnishing tax reporting information for Fund shares held in a nonqualified account, shareholder reports, and other communications from the Fund. For sales or exchanges of Fund shares acquired in a nonqualified account after 2011, your broker is required to report basis and holding period information to you and the IRS. Your broker may offer a choice of basis calculation methods. Contact your broker to determine which basis methods are available for your account.

■

The Fund or, in the case of sales of Fund shares in the secondary market, your broker, will generally be required by federal law to withhold tax on any distributions and proceeds paid to you if you have not provided a correct TIN or have not certified to the Fund or its agent, or your broker, as the case may be, that withholding does not apply.

■

For Authorized Participants Purchasing and Redeeming in Creation Units: An Authorized Participant that exchanges equity securities for one or more Creation Units will generally recognize a gain or a loss on the exchange. The gain or loss will be equal to the difference between (i) the market value of the Creation Unit(s) at the time and, (ii) the exchanger’s aggregate basis in the securities surrendered plus (or minus) the Cash Component paid (or received). A person who redeems one or more Creation Units for equity securities will generally recognize a gain or loss equal to the difference between (i) the exchanger’s basis in the Creation Unit(s) and, (ii) the aggregate market value of the securities received plus (or minus) the Cash Component received (or paid). The IRS, however, may assert that a loss realized upon an exchange of securities for Creation Unit(s) cannot be deducted currently under the rules governing “wash sales,” or on the basis that there has been no significant change in economic position. Persons exchanging securities should consult their own tax advisors with respect to whether wash sale rules apply and when a loss might be deductible. Any capital gain or loss realized upon a redemption of one or more Creation Units is generally treated as long-term capital gain or loss if the Creation Unit(s) have been held for more than one year and as short-term capital gain or loss if they have been held for one year or less. If you purchase or redeem Creation Units, you will be sent a confirmation statement showing how many shares you purchased or sold and at what price.

58	Prospectus 2019

Beta Advantage ^® ETFs

Premium/Discount Information

Information regarding how often the shares of the Fund traded on the Exchange at a price above (at a premium) or below (at a discount) the NAV of the Fund during the past four calendar quarters can be found at columbiathreadneedleetf.com/esgw for Columbia Sustainable Global Equity Income ETF, at columbiathreadneedleetf.com/esgn for Columbia Sustainable International Equity Income ETF and at columbiathreadneedleetf.com/esgs for Columbia Sustainable U.S. Equity Income ETF.

Prospectus 2019

59

Beta Advantage ^® ETFs

Financial Highlights — Columbia Sustainable Global Equity Income ETF

The financial highlights table is intended to help you understand the Fund’s financial performance for the past five fiscal years or, if shorter, the Fund’s period of operations. Certain information reflects financial results for a single Fund share. The total return in the table represents the rate that an investor would have earned (or lost) on an investment in the Fund assuming all dividends and distributions had been reinvested. This information has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report, along with the Fund’s financial statements, is included in the Fund’s annual report, which is available upon request.

    

  

(a)	The Fund commenced operations on June 13, 2016. Per share data and total return reflect activity from that date.

(b)	In addition to the fees and expenses that the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of any other funds in which it invests. Such indirect expenses are not included in the Fund’s reported expense ratios.
(c)	Annualized.

60	Prospectus 2019

Beta Advantage ^® ETFs

Financial Highlights — Columbia Sustainable International Equity Income ETF

The financial highlights table is intended to help you understand the Fund’s financial performance for the past five fiscal years or, if shorter, the Fund’s period of operations. Certain information reflects financial results for a single Fund share. The total return in the table represents the rate that an investor would have earned (or lost) on an investment in the Fund assuming all dividends and distributions had been reinvested. This information has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report, along with the Fund’s financial statements, is included in the Fund’s annual report, which is available upon request.

    

  

(a)	The Fund commenced operations on June 13, 2016. Per share data and total return reflect activity from that date.

(b)	In addition to the fees and expenses that the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of any other funds in which it invests. Such indirect expenses are not included in the Fund’s reported expense ratios.
(c)	Annualized.

Prospectus 2019

61

Beta Advantage ^® ETFs

Financial Highlights — Columbia Sustainable U.S. Equity Income ETF

The financial highlights table is intended to help you understand the Fund’s financial performance for the past five fiscal years or, if shorter, the Fund’s period of operations. Certain information reflects financial results for a single Fund share. The total return in the table represents the rate that an investor would have earned (or lost) on an investment in the Fund assuming all dividends and distributions had been reinvested. This information has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report, along with the Fund’s financial statements, is included in the Fund’s annual report, which is available upon request.

    

  

(a)	The Fund commenced operations on June 13, 2016. Per share data and total return reflect activity from that date.

(b)	In addition to the fees and expenses that the Fund bears directly, the Fund indirectly bears a pro rata share of the fees and expenses of any other funds in which it invests. Such indirect expenses are not included in the Fund’s reported expense ratios.
(c)	Annualized.

62	Prospectus 2019

[This page intentionally left blank]

Beta Advantage ^® ETFs

225 Franklin Street
Boston, MA 02110