Principal Risks of Investing in the Fund

Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of principal risks of investing in the Fund.

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Interest Rate Risk — The market value of bonds and other fixed-income securities changes in response to interest rate changes and other factors. Interest rate risk is the risk that prices of bonds and other fixed-income securities will increase as interest rates fall and decrease as interest rates rise.

The Fund may be subject to a greater risk of rising interest rates due to the current period of historically low rates. For example, if interest rates increase by 1%, assuming a current portfolio duration of ten years, and all other factors being equal, the value of the Fund’s investments would be expected to decrease by 10%. The magnitude of these fluctuations in the market price of bonds and other fixed-income securities is generally greater for those securities with longer maturities. Fluctuations in the market price of the Fund’s investments will not affect interest income derived from instruments already owned by the Fund, but will be reflected in the Fund’s net asset value. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by Fund management.

To the extent the Fund invests in debt securities that may be prepaid at the option of the obligor (such as mortgage-backed securities), the sensitivity of such securities to changes in interest rates may increase (to the detriment of the Fund) when interest rates rise. Moreover, because rates on certain floating rate debt securities typically reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause some fluctuations in the net asset value of the Fund to the extent that it invests in floating rate debt securities.

These basic principles of bond prices also apply to U.S. Government securities. A security backed by the “full faith and credit” of the U.S. Government is guaranteed only as to its stated interest rate and face value at maturity, not its current market price. Just like other fixed-income securities, government-guaranteed securities will fluctuate in value when interest rates change.

A general rise in interest rates has the potential to cause investors to move out of fixed-income securities on a large scale, which may increase redemptions from funds that hold large amounts of fixed-income securities. Heavy redemptions could cause the Fund to sell assets at inopportune times or at a loss or depressed value and could hurt the Fund’s performance.

Credit Risk — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will not be able to make payments of interest and principal when due. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer. The degree of credit risk depends on both the financial condition of the issuer and the terms of the obligation.

Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these obligations to fall.

Prepayment Risk — When interest rates fall, certain obligations will be paid off by the obligor more quickly than originally anticipated, and the Fund may have to invest the proceeds in securities with lower yields.

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Volatility Risk — Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.

Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation.

Market and Illiquidity Risk — The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.

Valuation Risk — Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them.

Hedging Risk — Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences.

Tax Risk — Certain aspects of the tax treatment of derivative instruments, including swap agreements and commodity-linked derivative instruments, are currently unclear and may be affected by changes in legislation, regulations or other legally binding authority. Such treatment may be less favorable than that given to a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments.

Regulatory Risk — Derivative contracts, including, without limitation, swaps, currency forwards and non-deliverable forwards, are subject to regulation under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) in the United States and under comparable regimes in Europe, Asia and other non-U.S. jurisdictions. Under the Dodd-Frank Act, certain derivatives are subject to margin requirements and swap dealers are required to collect margin from the Fund with respect to such derivatives. Specifically, regulations are now in effect that require swap dealers to post and collect variation margin (comprised of specified liquid instruments and subject to a required haircut) in connection with trading of over-the-counter (“OTC”) swaps with the Fund. Shares of investment companies (other than certain money market funds) may not be posted as collateral under these regulations. Requirements for posting of initial margin in connection with OTC swaps will be phased-in through 2020. In addition, regulations adopted by global prudential regulators that are now in effect require certain bank-regulated counterparties and certain of their affiliates to include in certain financial contracts, including many derivatives contracts, terms that delay or restrict the rights of counterparties, such as the Fund, to terminate such contracts, foreclose upon collateral, exercise other default rights or restrict transfers of credit support in the event that the counterparty and/or its affiliates are subject to certain types of resolution or insolvency proceedings. The implementation of these requirements with respect to derivatives, as well as regulations under the Dodd-Frank Act regarding clearing, mandatory trading and margining of other derivatives, may increase the costs and risks to the Fund of trading in these instruments and, as a result, may affect returns to investors in the Fund.

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Inflation-indexed bonds are fixed-income securities whose principal value is periodically adjusted according to the rate of inflation. If the index measuring inflation falls, the principal value of inflation-indexed bonds will be adjusted downward, and consequently the interest payable on these securities (calculated with respect to a smaller principal amount) will be reduced.

Repayment of the original bond principal upon maturity (as adjusted for inflation) is guaranteed in the case of U.S. Treasury inflation-indexed bonds. For bonds that do not provide a similar guarantee, the adjusted principal value of the bond repaid at maturity may be less than the original principal value.

The value of inflation-indexed bonds is expected to change in response to changes in real interest rates. Real interest rates are tied to the relationship between nominal interest rates and the rate of inflation. If nominal interest rates increase at a faster rate than inflation, real interest rates may rise, leading to a decrease in value of inflation-indexed bonds. Short-term increases in inflation may lead to a decline in value. Any increase in the principal amount of an inflation-indexed bond will be considered taxable ordinary income, even though investors do not receive their principal until maturity.

Periodic adjustments for inflation to the principal amount of an inflation-indexed bond may give rise to original issue discount, which will be includable in the Fund’s gross income. Due to original issue discount, the Fund may be required to make annual distributions to shareholders that exceed the cash received, which may cause the Fund to liquidate certain investments when it is not advantageous to do so. Also, if the principal value of an inflation-indexed bond is adjusted downward due to deflation, amounts previously distributed in the taxable year may be characterized in some circumstances as a return of capital.

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In order to qualify as a regulated investment company, at least 90% of the Fund’s gross income for the taxable year must be “qualifying income.” The Fund anticipates treating the income and gain generated from investments in controlled foreign subsidiaries that invest in physical commodities and/or commodity-linked derivative instruments as “qualifying income” for regulated investment company qualification purposes. However, there can be no assurance that the Internal Revenue Service (the “IRS”) will agree with treating such income and gain as “qualifying income.” If the IRS makes an adverse determination relating to the treatment of such income and gain, the Fund would likely need to change its investment strategies, which could adversely affect the Fund. The IRS has proposed regulations that, if finalized in current form, would specify that a subpart F income inclusion for U.S. federal income tax purposes will be treated as qualifying income only to the extent that the Subsidiary makes distributions out of its earnings and profits in the same taxable year.

Principal Risks of Investing in the Fund

Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of principal risks of investing in the Fund.

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Interest Rate Risk — The market value of bonds and other fixed-income securities changes in response to interest rate changes and other factors. Interest rate risk is the risk that prices of bonds and other fixed-income securities will increase as interest rates fall and decrease as interest rates rise.

The Fund may be subject to a greater risk of rising interest rates due to the current period of historically low rates. For example, if interest rates increase by 1%, assuming a current portfolio duration of ten years, and all other factors being equal, the value of the Fund’s investments would be expected to decrease by 10%. The magnitude of these fluctuations in the market price of bonds and other fixed-income securities is generally greater for those securities with longer maturities. Fluctuations in the market price of the Fund’s investments will not affect interest income derived from instruments already owned by the Fund, but will be reflected in the Fund’s net asset value. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by Fund management.

To the extent the Fund invests in debt securities that may be prepaid at the option of the obligor (such as mortgage-backed securities), the sensitivity of such securities to changes in interest rates may increase (to the detriment of the Fund) when interest rates rise. Moreover, because rates on certain floating rate debt securities typically reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause some fluctuations in the net asset value of the Fund to the extent that it invests in floating rate debt securities.

These basic principles of bond prices also apply to U.S. Government securities. A security backed by the “full faith and credit” of the U.S. Government is guaranteed only as to its stated interest rate and face value at maturity, not its current market price. Just like other fixed-income securities, government-guaranteed securities will fluctuate in value when interest rates change.

A general rise in interest rates has the potential to cause investors to move out of fixed-income securities on a large scale, which may increase redemptions from funds that hold large amounts of fixed-income securities. Heavy redemptions could cause the Fund to sell assets at inopportune times or at a loss or depressed value and could hurt the Fund’s performance.

Credit Risk — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will not be able to make payments of interest and principal when due. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer. The degree of credit risk depends on both the financial condition of the issuer and the terms of the obligation.

Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these obligations to fall.

Prepayment Risk — When interest rates fall, certain obligations will be paid off by the obligor more quickly than originally anticipated, and the Fund may have to invest the proceeds in securities with lower yields.

Volatility Risk — Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.

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Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation.

Market and Illiquidity Risk — The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.

Valuation Risk — Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them.

Hedging Risk — Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences.

Tax Risk — Certain aspects of the tax treatment of derivative instruments, including swap agreements and commodity-linked derivative instruments, are currently unclear and may be affected by changes in legislation, regulations or other legally binding authority. Such treatment may be less favorable than that given to a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments.

Regulatory Risk — Derivative contracts, including, without limitation, swaps, currency forwards and non-deliverable forwards, are subject to regulation under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) in the United States and under comparable regimes in Europe, Asia and other non-U.S. jurisdictions. Under the Dodd-Frank Act, certain derivatives are subject to margin requirements and swap dealers are required to collect margin from the Fund with respect to such derivatives. Specifically, regulations are now in effect that require swap dealers to post and collect variation margin (comprised of specified liquid instruments and subject to a required haircut) in connection with trading of over-the-counter (“OTC”) swaps with the Fund. Shares of investment companies (other than certain money market funds) may not be posted as collateral under these regulations. Requirements for posting of initial margin in connection with OTC swaps will be phased-in through 2020. In addition, regulations adopted by global prudential regulators that are now in effect require certain bank-regulated counterparties and certain of their affiliates to include in certain financial contracts, including many derivatives contracts, terms that delay or restrict the rights of counterparties, such as the Fund, to terminate such contracts, foreclose upon collateral, exercise other default rights or restrict transfers of credit support in the event that the counterparty and/or its affiliates are subject to certain types of resolution or insolvency proceedings. The implementation of these requirements with respect to derivatives, as well as regulations under the Dodd-Frank Act regarding clearing, mandatory trading and margining of other derivatives, may increase the costs and risks to the Fund of trading in these instruments and, as a result, may affect returns to investors in the Fund.

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In order to qualify as a regulated investment company, at least 90% of the Fund’s gross income for the taxable year must be “qualifying income.” The Fund anticipates treating the income and gain generated from investments in controlled foreign subsidiaries that invest in physical commodities and/or commodity-linked derivative instruments as “qualifying income” for regulated investment company qualification purposes. However, there can be no assurance that the Internal Revenue Service (the “IRS”) will agree with treating such income and gain as “qualifying income.” If the IRS makes an adverse determination relating to the treatment of such income and gain, the Fund would likely need to change its investment strategies, which could adversely affect the Fund. The IRS has proposed regulations that, if finalized in current form, would specify that a subpart F income inclusion for U.S. federal income tax purposes will be treated as qualifying income only to the extent that the Subsidiary makes distributions out of its earnings and profits in the same taxable year.

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Investment Risks

This section contains a discussion of the general risks of investing in the Funds. The “Investment Objectives and Policies” section in the SAI also includes more information about the Fund, its investments and the related risks. As with any fund, there can be no guarantee that the Funds will meet their investment objectives or that a Fund’s performance will be positive for any period of time. An investment in a Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or by any bank or governmental agency. Each risk noted below is applicable to each Fund unless the specific Fund or Funds are noted in a parenthetical.

Principal Risks of Investing in a Fund:

The market for corporate loans may be subject to irregular trading activity and wide bid/ask spreads.

The corporate loans in which the Fund invests are subject to the risk of loss of principal and income. Although borrowers frequently provide collateral to secure repayment of these obligations they do not always do so. If they do provide collateral, the value of the collateral may not completely cover the borrower’s obligations at the time of a default. If a borrower files for protection from its creditors under the U.S. bankruptcy laws, these laws may limit the

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Fund’s rights to its collateral. In addition, the value of collateral may erode during a bankruptcy case. In the event of a bankruptcy, the holder of a corporate loan may not recover its principal, may experience a long delay in recovering its investment and may not receive interest during the delay.

Interest Rate Risk — The market value of bonds and other fixed-income securities changes in response to interest rate changes and other factors. Interest rate risk is the risk that prices of bonds and other fixed-income securities will increase as interest rates fall and decrease as interest rates rise. The Fund may be subject to a greater risk of rising interest rates due to the current period of historically low rates. For example, if interest rates increase by 1%, assuming a current portfolio duration of ten years, and all other factors being equal, the value of the Fund’s investments would be expected to decrease by 10%. The magnitude of these fluctuations in the market price of bonds and other fixed-income securities is generally greater for those securities with longer maturities. Fluctuations in the market price of the Fund’s investments will not affect interest income derived from instruments already owned by the Fund, but will be reflected in the Fund’s net asset value. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by Fund management. To the extent the Fund invests in debt securities that may be prepaid at the option of the obligor (such as mortgage-backed securities), the sensitivity of such securities to changes in interest rates may increase (to the detriment of the Fund) when interest rates rise. Moreover, because rates on certain floating rate debt securities typically reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause some fluctuations in the net asset value of the Fund to the extent that it invests in floating rate debt securities. These basic principles of bond prices also apply to U.S. Government securities. A security backed by the “full faith and credit” of the U.S. Government is guaranteed only as to its stated interest rate and face value at maturity, not its current market price. Just like other fixed-income securities, government-guaranteed securities will fluctuate in value when interest rates change.

Following the financial crisis that began in 2007, the Federal Reserve has attempted to stabilize the economy and support the economic recovery by keeping the federal funds rate (the interest rate at which depository institutions lend reserve balances to other depository institutions overnight) at or near zero percent. In addition, as part of its monetary stimulus program known as quantitative easing, the Federal Reserve has purchased on the open market large quantities of securities issued or guaranteed by the U.S. Government, its agencies or instrumentalities. As the Federal Reserve “tapers” or reduces the amount of securities it purchases pursuant to quantitative easing, and/or if the Federal Reserve raises the federal funds rate, there is a risk that interest rates will rise. A general rise in interest rates has the potential to cause investors to move out of fixed-income securities on a large scale, which may increase redemptions from mutual funds that hold large amounts of fixed-income securities. Heavy redemptions could cause the Fund to sell assets at inopportune times or at a loss or depressed value and could hurt the Fund’s performance.

During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns. Certain countries have recently experienced negative interest rates on certain fixed-income instruments. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, may result in heightened market volatility and may detract from Fund performance to the extent the Fund is exposed to such interest rates.

Credit Risk — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will not be able to make payments of interest and principal when due. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer. The degree of credit risk depends on both the financial condition of the issuer and the terms of the obligation.

Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these obligations to fall. Rising interest rates tend to extend the duration of securities, making them more sensitive to changes in interest rates. The value of longer-term securities generally changes more in response to changes in interest rates than shorter-term securities. As a result, in a period of rising interest rates, securities may exhibit additional volatility and may lose value.

Prepayment Risk — When interest rates fall, certain obligations will be paid off by the obligor more quickly than originally anticipated, and the Fund may have to invest the proceeds in securities with lower yields. In periods of falling interest rates, the rate of prepayments tends to increase (as does price fluctuation) as borrowers are motivated to pay off debt and refinance at new lower rates. During such periods, reinvestment of the prepayment proceeds by the management team will generally be at lower rates of return than the return on the assets that were prepaid. Prepayment reduces the yield to maturity and the average life of the security.

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Volatility Risk — The Fund’s use of derivatives may reduce the Fund’s returns and/or increase volatility. Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.

Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation.

Market and Illiquidity Risk — Some derivatives are more sensitive to interest rate changes and market price fluctuations than other securities. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately. The Fund could also suffer losses related to its derivatives positions as a result of unanticipated market movements, which losses are potentially unlimited. Finally, BlackRock may not be able to predict correctly the direction of securities prices, interest rates and other economic factors, which could cause the Fund’s derivatives positions to lose value.

Valuation Risk — Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them. Derivatives may also expose the Fund to greater risk and increase its costs. Certain transactions in derivatives involve substantial leverage risk and may expose the Fund to potential losses that exceed the amount originally invested by the Fund.

Hedging Risk — When a derivative is used as a hedge against a position that the Fund holds, any loss generated by the derivative generally should be substantially offset by gains on the hedged investment, and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences noted below.

Tax Risk — The federal income tax treatment of a derivative may not be as favorable as a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments. As a result, a larger portion of the Fund’s distributions may be treated as ordinary income rather than capital gains. In addition, certain derivatives are subject to mark-to-market or straddle provisions of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”). If such provisions are applicable, there could be an increase (or decrease) in the amount of taxable dividends paid by the Fund. In addition, the tax treatment of certain derivatives, such as swaps, is unsettled and may be subject to future legislation, regulation or administrative pronouncements issued by the Internal Revenue Service (the “IRS”).

Regulatory Risk — Derivative contracts, including, without limitation, swaps, currency forwards and non-deliverable forwards, are subject to regulation under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) in the United States and under comparable regimes in Europe, Asia and other non-U.S. jurisdictions. Under the Dodd-Frank Act, certain derivatives are subject to margin requirements and swap dealers are required to collect margin from the Fund with respect to such derivatives. Specifically, regulations are now in effect that require swap dealers to post and collect variation margin (comprised of specified liquid instruments and subject to a required haircut) in connection with trading of over-the-counter (“OTC”) swaps with the Fund. Shares of investment companies (other than certain money market funds) may not be posted as collateral under these regulations. Requirements for posting of initial margin in connection with OTC swaps will be phased-in through 2020. In addition, regulations adopted by global prudential regulators that are now in effect require certain bank-regulated counterparties and certain of their affiliates to include in certain financial contracts, including many derivatives contracts, terms that delay or restrict the rights of counterparties, such as the Fund, to terminate such contracts, foreclose upon collateral, exercise other default rights or restrict transfers of credit support in the event that the counterparty and/or its affiliates are subject to certain types of resolution or insolvency proceedings. The implementation of these requirements with respect to derivatives, as well as regulations under the Dodd-Frank Act regarding clearing, mandatory trading and margining of other derivatives, may increase the costs and risks to the Fund of trading in these instruments and, as a result, may affect returns to investors in the Fund.

Future regulatory developments may impact the Fund’s ability to invest or remain invested in certain derivatives. Legislation or regulation may also change the way in which the Fund itself is regulated. BlackRock cannot predict the effects of any new governmental regulation that may be implemented on the ability of the Fund to use swaps or any other financial derivative product, and there can be no assurance that any new governmental regulation will not adversely affect the Fund’s ability to achieve its investment objective.

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Risks Specific to Certain Derivatives Used by the Fund

Swaps – Swap agreements, including total return swaps that may be referred to as contracts for difference, are two-party contracts entered into for periods ranging from a few weeks to more than one year. In a standard “swap” transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments, which can be adjusted for an interest factor. Swap agreements involve the risk that the party with whom the Fund has entered into the swap will default on its obligation to pay the Fund and the risk that the Fund will not be able to meet its obligations to pay the other party to the agreement. Swap agreements may also involve the risk that there is an imperfect correlation between the return on the Fund’s obligation to its counterparty and the return on the referenced asset. In addition, swap agreements are subject to market and illiquidity risk, leverage risk and hedging risk.

Credit Default Swaps – Credit default swaps may have as reference obligations one or more securities that are not currently held by the Fund. The protection “buyer” may be obligated to pay the protection “seller” an up-front payment or a periodic stream of payments over the term of the contract, provided generally that no credit event on a reference obligation has occurred. Credit default swaps involve special risks in addition to those mentioned above because they are difficult to value, are highly susceptible to illiquid investments risk and credit risk, and generally pay a return to the party that has paid the premium only in the event of an actual default by the issuer of the underlying obligation (as opposed to a credit downgrade or other indication of financial difficulty).

Forward Foreign Currency Exchange Contracts – Forward foreign currency exchange transactions are OTC contracts to purchase or sell a specified amount of a specified currency or multinational currency unit at a price and future date set at the time of the contract. Forward foreign currency exchange contracts do not eliminate fluctuations in the value of non-U.S. securities but rather allow the Fund to establish a fixed rate of exchange for a future point in time. This strategy can have the effect of reducing returns and minimizing opportunities for gain.

Futures – Futures are standardized, exchange-traded contracts that obligate a purchaser to take delivery, and a seller to make delivery, of a specific amount of an asset at a specified future date at a specified price. The primary risks associated with the use of futures contracts and options are: (a) the imperfect correlation between the change in market value of the instruments held by the Fund and the price of the futures contract or option; (b) the possible lack of a liquid secondary market for a futures contract and the resulting inability to close a futures contract when desired; (c) losses caused by unanticipated market movements, which are potentially unlimited; (d) the investment adviser’s inability to predict correctly the direction of securities prices, interest rates, currency exchange rates and other economic factors; and (e) the possibility that the counterparty will default in the performance of its obligations.

Options – An option is an agreement that, for a premium payment or fee, gives the option holder (the purchaser) the right but not the obligation to buy (a “call option”) or sell (a “put option”) the underlying asset (or settle for cash in an amount based on an underlying asset, rate, or index) at a specified price (the “exercise price”) during a period of time or on a specified date. Investments in options are considered speculative. When the Fund purchases an option, it may lose the total premium paid for it if the price of the underlying security or other assets decreased, remained the same or failed to increase to a level at or beyond the exercise price (in the case of a call option) or increased, remained the same or failed to decrease to a level at or below the exercise price (in the case of a put option). If a put or call option purchased by the Fund were permitted to expire without being sold or exercised, its premium would represent a loss to the Fund. To the extent that the Fund writes or sells an option, if the decline or increase in the underlying asset is significantly below or above the exercise price of the written option, the Fund could experience a substantial loss.

Commodity-Linked Derivatives – The value of a commodity-linked derivative investment typically is based upon the price movements of a commodity, a commodity futures contract or commodity index, or some other readily measurable economic variable. The value of commodity-linked derivative instruments may be affected by changes in overall market movements, volatility of the underlying benchmark, changes in interest rates, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. The value of commodity-linked derivatives will rise or fall in response to changes in the underlying commodity or related index. Investments in commodity-linked derivatives may be subject to greater volatility than non-derivative based investments. A highly liquid secondary market may not exist for certain commodity-linked derivatives, and there can be no assurance that one will develop.

Commodity-linked derivatives also may be subject to credit and interest rate risks that in general affect the values of fixed-income securities. Therefore, at maturity, the Fund may receive more or less principal than it originally invested. The Fund might receive interest payments that are more or less than the stated coupon interest payments.

In connection with the Fund’s direct and indirect investments in commodity-linked derivatives, the Fund will attempt to manage its counterparty exposure so as to limit its exposure to any one counterparty. However, due to the limited number of entities that may serve as counterparties (and which the Fund believes are creditworthy) at any one time the Fund may enter into swap agreements with a limited number of counterparties and may invest in

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commodity-linked notes issued by a limited number of issuers that will act as counterparties, which may increase the Fund’s exposure to counterparty credit risk. There can be no assurance that the Fund will be able to limit exposure to any one counterparty at all times.

Many emerging markets have histories of political instability and abrupt changes in policies. As a result, their governments are more likely to take actions that are hostile or detrimental to private enterprise or foreign investment than those of more developed countries, including expropriation of assets, confiscatory taxation, high rates of inflation or unfavorable diplomatic developments. In the past, governments of such nations have expropriated substantial amounts of private property, and most claims of the property owners have never been fully settled. There is no assurance that such expropriations will not reoccur. In such an event, it is possible that the Fund could lose the entire value of its investments in the affected market. Some countries have pervasive corruption and crime that may hinder investments. Certain emerging markets may also face other significant internal or external risks, including the risk of war, and ethnic, religious and racial conflicts. In addition, governments in many emerging market countries participate to a significant degree in their economies and securities markets, which may impair investment and economic growth. National policies that may limit the Fund’s investment opportunities include restrictions on investment in issuers or industries deemed sensitive to national interests.

Emerging markets may also have differing legal systems and the existence or possible imposition of exchange controls, custodial restrictions or other foreign or U.S. governmental laws or restrictions applicable to such investments. Sometimes, they may lack or be in the relatively early development of legal structures governing private and foreign investments and private property. Many emerging markets do not have income tax treaties with the United States, and as a result, investments by the Fund may be subject to higher withholding taxes in such countries. In addition, some countries with emerging markets may impose differential capital gains taxes on foreign investors.

Practices in relation to settlement of securities transactions in emerging markets involve higher risks than those in developed markets, in part because the Fund will need to use brokers and counterparties that are less well capitalized, and custody and registration of assets in some countries may be unreliable. The possibility of fraud, negligence, undue influence being exerted by the issuer or refusal to recognize ownership exists in some emerging markets, and, along with other factors, could result in ownership registration being completely lost. The Fund would absorb any loss resulting from such registration problems and may have no successful claim for compensation. In addition, communications between the United States and emerging market countries may be unreliable, increasing the risk of delayed settlements or losses of security certificates.

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Certain Risks of Holding Fund Assets Outside the United States — The Fund generally holds its foreign securities and cash in foreign banks and securities depositories. Some foreign banks and securities depositories may be recently organized or new to the foreign custody business. In addition, there may be limited or no regulatory oversight of their operations. Also, the laws of certain countries limit the Fund’s ability to recover its assets if a foreign bank, depository or issuer of a security, or any of their agents, goes bankrupt. In addition, it is often more expensive for the Fund to buy, sell and hold securities in certain foreign markets than in the United States. The increased expense of investing in foreign markets reduces the amount the Fund can earn on its investments and typically results in a higher operating expense ratio for the Fund than for investment companies invested only in the United States.

Currency Risk — Securities and other instruments in which the Fund invests may be denominated or quoted in currencies other than the U.S. dollar. For this reason, changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.

Generally, when the U.S. dollar rises in value against a foreign currency, a security denominated in that currency loses value because the currency is worth fewer U.S. dollars. Conversely, when the U.S. dollar decreases in value against a foreign currency, a security denominated in that currency gains value because the currency is worth more U.S. dollars. This risk, generally known as “currency risk,” means that a strong U.S. dollar will reduce returns for U.S. investors while a weak U.S. dollar will increase those returns.

Foreign Economy Risk — The economies of certain foreign markets may not compare favorably with the economy of the United States with respect to such issues as growth of gross national product, reinvestment of capital, resources and balance of payments position. Certain foreign economies may rely heavily on particular industries or foreign capital and are more vulnerable to diplomatic developments, the imposition of economic sanctions against a particular country or countries, changes in international trading patterns, trade barriers and other protectionist or retaliatory measures. Investments in foreign markets may also be adversely affected by governmental actions such as the imposition of capital controls, nationalization of companies or industries, expropriation of assets or the imposition of punitive taxes. In addition, the governments of certain countries may prohibit or impose substantial restrictions on foreign investments in their capital markets or in certain industries. Any of these actions could severely affect securities prices or impair the Fund’s ability to purchase or sell foreign securities or transfer the Fund’s assets or income back into the United States, or otherwise adversely affect the Fund’s operations.

Other potential foreign market risks include foreign exchange controls, difficulties in pricing securities, defaults on foreign government securities, difficulties in enforcing legal judgments in foreign courts and political and social instability. Diplomatic and political developments, including rapid and adverse political changes, social instability, regional conflicts, terrorism and war, could affect the economies, industries and securities and currency markets, and the value of the Fund’s investments, in non-U.S. countries. These factors are extremely difficult, if not impossible, to predict and take into account with respect to the Fund’s investments.

Governmental Supervision and Regulation/Accounting Standards — Many foreign governments do not supervise and regulate stock exchanges, brokers and the sale of securities to the same extent as such regulations exist in the United States. They also may not have laws to protect investors that are comparable to U.S. securities laws. For example, some foreign countries may have no laws or rules against insider trading. Insider trading occurs when a person buys or sells a company’s securities based on material non-public information about that company. In addition, some countries may have legal systems that may make it difficult for the Fund to vote proxies, exercise shareholder rights, and pursue legal remedies with respect to its foreign investments. Accounting standards in other countries are not necessarily the same as in the United States. If the accounting standards in another country do not require as much detail as U.S. accounting standards, it may be harder for Fund management to completely and accurately determine a company’s financial condition.

Settlement Risk — Settlement and clearance procedures in certain foreign markets differ significantly from those in the United States. Foreign settlement and clearance procedures and trade regulations also may involve certain risks (such as delays in payment for or delivery of securities) not typically associated with the settlement of U.S. investments.

At times, settlements in certain foreign countries have not kept pace with the number of securities transactions. These problems may make it difficult for the Fund to carry out transactions. If the Fund cannot settle or is delayed in settling a purchase of securities, it may miss attractive investment opportunities and certain of its assets may be uninvested with no return earned thereon for some period. If the Fund cannot settle or is delayed in settling a sale of securities, it may lose money if the value of the security then declines or, if it has contracted to sell the security to another party, the Fund could be liable for any losses incurred.

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European Economic Risk — The European financial markets have recently experienced volatility and adverse trends due to concerns about economic downturns in, or rising government debt levels of several European countries. These events may spread to other countries in Europe. These events may affect the value and liquidity of certain of the Fund’s investments.

Responses to the financial problems by European governments, central banks and others, including austerity measures and reforms, may not work, may result in social unrest and may limit future growth and economic recovery or have other unintended consequences. Further defaults or restructurings by governments and others of their debt could have additional adverse effects on economies, financial markets and asset valuations around the world. In addition, the United Kingdom has voted to withdraw from the European Union, and one or more other countries may withdraw from the European Union and/or abandon the Euro, the common currency of the European Union. The impact of these actions, especially if they occur in a disorderly fashion, is not clear but could be significant and far reaching.

Inflation-indexed bonds are fixed-income securities whose principal value is periodically adjusted according to the rate of inflation. If the index measuring inflation falls, the principal value of inflation-indexed bonds will be adjusted downward, and consequently the interest payable on these securities (calculated with respect to a smaller principal amount) will be reduced.

Repayment of the original bond principal upon maturity (as adjusted for inflation) is guaranteed in the case of U.S. Treasury inflation-indexed bonds. For bonds that do not provide a similar guarantee, the adjusted principal value of the bond repaid at maturity may be less than the original principal value.

The value of inflation-indexed bonds is expected to change in response to changes in real interest rates. Real interest rates are tied to the relationship between nominal interest rates and the rate of inflation. If nominal interest rates increase at a faster rate than inflation, real interest rates may rise, leading to a decrease in value of inflation-indexed bonds. Short-term increases in inflation may lead to a decline in value. Any increase in the principal amount of an inflation-indexed bond will be considered taxable ordinary income, even though investors do not receive their principal until maturity.

Periodic adjustments for inflation to the principal amount of an inflation-indexed bond may give rise to original issue discount, which will be includable in the Fund’s gross income. Due to original issue discount, the Fund may be required to make annual distributions to shareholders that exceed the cash received, which may cause the Fund to liquidate certain investments when it is not advantageous to do so. Also, if the principal value of an inflation-indexed bond is adjusted downward due to deflation, amounts previously distributed in the taxable year may be characterized in some circumstances as a return of capital.

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The credit rating of a high yield security does not necessarily address its market value risk. Ratings and market value may change from time to time, positively or negatively, to reflect new developments regarding the issuer.

Small movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain mortgage-backed securities. The Fund’s investments in asset-backed securities are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets. These securities also are subject to the risk of default on the underlying mortgages or assets, particularly during periods of economic downturn. Certain CMBS are issued in several classes with different levels of yield and credit protection. The Fund’s investments in CMBS with several classes may be in the lower classes that have greater risks than the higher classes, including greater interest rate, credit and prepayment risks.

Mortgage-backed securities may be either pass-through securities or collateralized mortgage obligations (“CMOs”). Pass-through securities represent a right to receive principal and interest payments collected on a pool of mortgages, which are passed through to security holders. CMOs are created by dividing the principal and interest payments collected on a pool of mortgages into several revenue streams (“tranches”) with different priority rights to portions of the underlying mortgage payments. Certain CMO tranches may represent a right to receive interest only (“IOs”), principal only (“POs”) or an amount that remains after floating-rate tranches are paid (an “inverse floater”). These securities are frequently referred to as “mortgage derivatives” and may be extremely sensitive to changes in interest rates. Interest rates on inverse floaters, for example, vary inversely with a short-term floating rate (which may be reset periodically). Interest rates on inverse floaters will decrease when short-term rates increase, and will increase when short-term rates decrease. These securities have the effect of providing a degree of investment leverage. In response to changes in market interest rates or other market conditions, the value of an inverse floater may increase or decrease at a multiple of the increase or decrease in the value of the underlying securities. If the Fund invests in CMO tranches (including CMO tranches issued by government agencies) and interest rates move in a manner not anticipated by Fund management, it is possible that the Fund could lose all or substantially all of its investment. Certain mortgage-backed securities in which the Fund may invest may also provide a degree of investment leverage, which could cause the Fund to lose all or substantially all of its investment.

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The mortgage market in the United States has experienced difficulties that may adversely affect the performance and market value of certain of the Fund’s mortgage-related investments. Delinquencies and losses on mortgage loans (including subprime and second-lien mortgage loans) generally have increased and may continue to increase, and a decline in or flattening of real estate values (as has been experienced and may continue to be experienced in many housing markets) may exacerbate such delinquencies and losses. Also, a number of mortgage loan originators have experienced serious financial difficulties or bankruptcy. Reduced investor demand for mortgage loans and mortgage-related securities and increased investor yield requirements have caused limited liquidity in the secondary market for mortgage-related securities, which can adversely affect the market value of mortgage-related securities. It is possible that such limited liquidity in such secondary markets could continue or worsen.

Asset-backed securities entail certain risks not presented by mortgage-backed securities, including the risk that in certain states it may be difficult to perfect the liens securing the collateral backing certain asset-backed securities. In addition, certain asset-backed securities are based on loans that are unsecured, which means that there is no collateral to seize if the underlying borrower defaults.

The securities of small cap and emerging growth companies generally trade in lower volumes and are subject to greater and more unpredictable price changes than larger cap securities or the market as a whole. In addition, small cap and emerging growth securities may be particularly sensitive to changes in interest rates, borrowing costs and earnings. Investing in small cap and emerging growth securities requires a longer term view.

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Structured notes may be positively or negatively indexed, so the appreciation of the reference measure may produce an increase or a decrease in the interest rate or the value of the principal at maturity. The rate of return on structured notes may be determined by applying a multiplier to the performance or differential performance of reference measures. Application of a multiplier involves leverage that will serve to magnify the potential for gain and the risk of loss.

The purchase of structured notes exposes the Fund to the credit risk of the issuer of the structured product. Structured notes may also be more volatile, less liquid, and more difficult to price accurately than less complex securities and instruments or more traditional debt securities.

In order to qualify as a regulated investment company, at least 90% of the Fund’s gross income for the taxable year must be “qualifying income.” The Fund anticipates treating the income and gain generated from investments in controlled foreign subsidiaries that invest in physical commodities and/or commodity-linked derivative instruments as “qualifying income” for regulated investment company qualification purposes. However, there can be no assurance that the IRS will agree with treating such income and gain as “qualifying income.” If the IRS makes an adverse determination relating to the treatment of such income and gain, the Fund would likely need to change its investment strategies, which could adversely affect the Fund. The IRS has proposed regulations that, if finalized in current form, would specify that a subpart F income inclusion for U.S. federal income tax purposes will be treated as qualifying income only to the extent that the Subsidiary makes distributions out of its earnings and profits in the same taxable year.

A Fund may also be subject to certain other risks associated with its investments and investment strategies, including:

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Account Information

Details About the Share Class

Each Fund currently offers multiple share classes (Institutional Shares in this prospectus), each with its own expense structure, allowing you to invest in the way that best suits your needs. Each share class represents an ownership interest in the same investment portfolio. When you choose your class of shares, you should consider the size of your investment and how long you plan to hold your shares.

Only certain investors may buy Institutional Shares. Either your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock and its affiliates) (each a “Financial Intermediary”) can help you determine whether you are eligible to buy Institutional Shares.

The Fund’s shares are distributed by BlackRock Investments, LLC (the “Distributor”), an affiliate of BlackRock.

The table below summarizes key features of Institutional Shares of the Fund.

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Institutional Shares are not subject to any sales charge. Only certain investors are eligible to buy Institutional Shares. Your Financial Intermediary can help you determine whether you are eligible to buy Institutional Shares. A Fund may permit a lower initial investment for certain investors if their purchase, combined with purchases by other investors received together by a Fund, meets the minimum investment requirement.

Institutional Shares may also be available on certain brokerage platforms. An investor transacting in Institutional Shares on such brokerage platforms through a broker acting as an agent for the investor may be required to pay a commission and/or other forms of compensation to the broker. Shares of a Fund are available in other share classes that have different fees and expenses.

Eligible Institutional Share investors include the following:

The Funds reserve the right to modify or waive the above-stated policies at any time.

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Distribution and Shareholder Servicing Payments

Other Payments by the Funds

BlackRock, on behalf of the Funds, may enter into agreements with a Financial Intermediary pursuant to which the Funds will pay a Financial Intermediary for administrative, networking, recordkeeping, sub-transfer agency, sub-accounting and/or shareholder services. These payments are generally based on either: (1) a percentage of the average daily net assets of Fund shareholders serviced by a Financial Intermediary or (2) a fixed dollar amount for each account serviced by a Financial Intermediary. The aggregate amount of these payments may be substantial.

Other Payments by BlackRock

From time to time, BlackRock, the Distributor or their affiliates also may pay a portion of the fees for administrative, networking, recordkeeping, sub-transfer agency, sub-accounting and shareholder services described above at its or their own expense and out of its or their profits. BlackRock, the Distributor and their affiliates may also compensate affiliated and unaffiliated Financial Intermediaries for the sale and distribution of shares of the Funds. These payments would be in addition to Fund payments described in this prospectus and may be a fixed dollar amount, may be based on the number of customer accounts maintained by the Financial Intermediary, or may be based on a percentage of the value of shares sold to, or held by, customers of the Financial Intermediary or may be calculated on another basis. The aggregate amount of these payments by BlackRock, the Distributor and their affiliates may be substantial and, in some circumstances, may create an incentive for a Financial Intermediary, its employees or associated persons to recommend or sell shares of a Fund to you.

Please contact your Financial Intermediary for details about payments it may receive from a Fund or from BlackRock, the Distributor or their affiliates. For more information, see the SAI.

Right of Accumulation

Investors have a “right of accumulation” under which any of the following may be combined with the amount of the current purchase in determining whether an investor qualifies for a breakpoint and a reduced front-end sales charge:

Financial Intermediaries may value current holdings of their customers differently for purposes of determining whether an investor qualifies for a breakpoint and a reduced front-end sales charge, although customers of the same Financial Intermediary will be treated similarly. In order to use this right, the investor must alert BlackRock to the existence of any previously purchased shares.

How to Buy, Sell, Exchange and Transfer Shares

The chart on the following pages summarizes how to buy, sell, exchange and transfer shares through your Financial Intermediary. You may also buy, sell, exchange and transfer shares through BlackRock if your account is held directly with BlackRock. To learn more about buying, selling, exchanging or transferring shares through BlackRock, call (800) 537-4942. Because the selection of a mutual fund involves many considerations, your Financial Intermediary may help you with this decision.

With certain limited exceptions, the Funds are generally available only to investors residing in the United States and may not be distributed by a foreign Financial Intermediary. Under this policy, in order to accept new accounts or additional investments (including by way of exchange from another BlackRock Fund) into existing accounts, each Fund generally requires that (i) a shareholder that is a natural person be a U.S. citizen or resident alien, in each case residing within the United States or a U.S. territory (including APO/FPO/DPO addresses), and have a valid U.S. taxpayer identification number, and (ii) a Financial Intermediary or a shareholder that is an entity be domiciled in the United States and have a valid U.S. taxpayer identification number or be domiciled in a U.S. territory and have a valid U.S. taxpayer identification number or IRS Form W-8. Any existing account that is updated to reflect a non-U.S. address will also be restricted from making additional investments.

The Funds may reject any purchase order, modify or waive the minimum initial or subsequent investment requirements for any shareholders and suspend and resume the sale of any share class of the Funds at any time for any reason. In addition, the Funds may waive certain requirements regarding the purchase, sale, exchange or transfer of shares described below.

Under certain circumstances, if no activity occurs in an account within a time period specified by state law, a shareholder’s shares in a Fund may be transferred to that state.

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