The market for municipal bonds may be less liquid
than for other types of debt securities, and it may be harder for the Fund to buy and sell municipal bonds, especially on short notice. There may be less publicly available
information about the financial condition of municipal security issuers than for issuers of other types of securities. As a result, municipal securities may be more difficult to value accurately. A default or insolvency of certain issuers of municipal bonds may be subject to proceedings
that are significantly different from corporate bankruptcy proceedings, and the Fund’s ability to recover assets may be limited.
Risk of Investing in the U.S. Investing in U.S. issuers subjects the Fund
to legal, regulatory, political, currency, security, and economic risks that are specific to the U.S. Certain changes in the U.S., such as a weakening of the U.S. economy or a
decline in its financial markets, may have an adverse effect on U.S. issuers.
Interest Rate Risk. Interest rate risk refers to the risk of fluctuations
in the value of a fixed-income security due to changes in the general level of interest rates. Interest rate changes can be sudden and unpredictable and are influenced by a number
of factors, including government policy, monetary policy, inflation expectations, perceptions of risk, and supply and demand for fixed-income securities. An increase in interest rates generally will cause the value of fixed-income securities to decline.
Securities with longer maturities generally are more sensitive to interest rate changes and subject to greater fluctuations in value. Changes in interest rates may have unpredictable effects on fixed-income markets and result in heightened volatility
and lower liquidity for certain instruments, which may adversely affect a Fund’s performance. During periods of very low or negative interest rates, a Fund may be unable to maintain positive returns or pay dividends to shareholders.
Market Risk. The Fund could lose money over short periods due to
short-term market movements and over longer periods during more prolonged market downturns. Local, regional or global events such as war, acts of terrorism, pandemics or other
public health issues, recessions, the prospect or occurrence of a sovereign default or other financial crisis, or other events could have a significant impact on the Fund and its investments and could result in increased premiums or discounts to the
Fund’s NAV.
Index-Related Risk. The Index Provider may rely on various sources of information to assess the criteria of
components of the Underlying Index, including information that may be based on assumptions and estimates. Neither the Fund nor BFA can offer assurances that the Index Provider’s methodology or sources of information will provide an accurate assessment of
included components or will result in the Fund meeting its investment objective. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur, and the Index Provider may not identify
or correct them promptly or at all, which may have an adverse impact on the Fund and its shareholders. Unusual market conditions or other unforeseen circumstances (such as natural
disasters, political unrest or war) may impact the Index Provider or a third-party data provider and could cause the Index Provider to postpone a scheduled rebalance. This could
cause the Underlying Index to vary from its normal or expected composition.
Asset Class Risk. The securities and other assets in the Underlying Index
or in the Fund’s portfolio may underperform in comparison to financial markets generally, a particular financial market, another index, or other asset classes.
Authorized Participant Concentration Risk. An “Authorized Participant” is a member or participant of a clearing agency
registered with the SEC, which has a written agreement with the Fund or one of its service providers that allows the Authorized Participant to place orders for the purchase and redemption of creation units (“Creation Units”). Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund. There are a limited number of
institutions that may act as Authorized Participants for the Fund, including on an agency basis on behalf of other market participants. No Authorized Participant is obligated to
engage in creation or redemption transactions. To the extent that Authorized Participants exit the business or do not place creation or redemption orders for the Fund and no other
Authorized Participant places orders, Fund shares are more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.
Call Risk. During periods of falling interest rates, an issuer of a callable debt obligation held by the Fund
may “call” or repay the debt obligation before its stated maturity, and the Fund may have to reinvest the proceeds in instruments with
lower yields, which would result in a decline in the Fund's income, or in instruments with greater risks or with other less favorable features.
Concentration Risk. The Fund may be susceptible to an increased risk of loss, including losses due to adverse
events that affect the Fund’s investments more than the market as a whole, to the extent that the Fund’s investments are concentrated in the securities or other assets of one or more issuers, countries or other geographic units, markets, industries, project types, or asset classes.
Credit Risk. Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income
security may be unable or unwilling, or may be perceived as unable or unwilling, to make timely principal and/or interest payments or to otherwise honor its obligations. The credit rating assigned to a security or its issuer does not necessarily reflect the issuer’s current financial condition or an investment’s volatility or liquidity. An actual or perceived decline in an issuer’s creditworthiness may result in a