0001176194

N-CSRS

General Description of Registrant [Abstract]

9.	PRINCIPAL RISKS

In the normal course of business, the Trusts invest in securities or other instruments and may enter into certain transactions, and such activities subject each Trust to various risks, including among others, fluctuations in the market (market risk) or failure of an issuer to meet all of its obligations. The value of securities or other instruments may also be affected by various factors, including, without limitation: (i) the general economy; (ii) the overall market as well as local, regional or global political and/or social instability; (iii) regulation, taxation or international tax treaties between various countries; or (iv) currency, interest rate and price fluctuations. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, recessions, or other events could have a significant impact on the Trusts and their investments.

The Trusts may hold a significant amount of bonds subject to calls by the issuers at defined dates and prices. When bonds are called by issuers and the Trusts reinvest the proceeds received, such investments may be in securities with lower yields than the bonds originally held, and correspondingly, could adversely impact the yield and total return performance of a Trust.

A Trust structures and “sponsors” the TOB Trusts in which it holds TOB Residuals and has certain duties and responsibilities, which may give rise to certain additional risks including, but not limited to, compliance, securities law and operational risks.

As short-term interest rates rise, the Trusts’ investments in the TOB Trusts may adversely affect the Trusts’ net investment income and dividends to Common Shareholders. Also, fluctuations in the market value of municipal bonds deposited into the TOB Trust may adversely affect the Trusts’ NAVs per share.

The U.S. Securities and Exchange Commission (“SEC”) and various federal banking and housing agencies have adopted credit risk retention rules for securitizations (the “Risk Retention Rules”). The Risk Retention Rules would require the sponsor of a TOB Trust to retain at least 5% of the credit risk of the underlying assets supporting the TOB Trust’s municipal bonds. The Risk Retention Rules may adversely affect the Trusts’ ability to engage in TOB Trust transactions or increase the costs of such transactions in certain circumstances.

TOB Trusts constitute an important component of the municipal bond market. Any modifications or changes to rules governing TOB Trusts may adversely impact the municipal market and the Trusts, including through reduced demand for and liquidity of municipal bonds and increased financing costs for municipal issuers. The ultimate impact of any potential modifications on the TOB Trust market and the overall municipal market is not yet certain.

Each Trust may invest without limitation in illiquid or less liquid investments or investments in which no secondary market is readily available or which are otherwise illiquid, including private placement securities. A Trust may not be able to readily dispose of such investments at prices that approximate those at which a Trust could sell such investments if they were more widely traded and, as a result of such illiquidity, a Trust may have to sell other investments or engage in borrowing transactions if necessary to raise funds to meet its obligations. Limited liquidity can also affect the market price of investments, thereby adversely affecting a Trust’s NAV and ability to make dividend distributions. Privately issued debt securities are often of below investment grade quality, frequently are unrated and present many of the same risks as investing in below investment grade public debt securities.

Market Risk: Each Trust may be exposed to prepayment risk, which is the risk that borrowers may exercise their option to prepay principal earlier than scheduled during periods of declining interest rates, which would force each Trust to reinvest in lower yielding securities. Each Trust may also be exposed to reinvestment risk, which is the risk that income from each Trust’s portfolio will decline if each Trust invests the proceeds from matured, traded or called fixed-income securities at market interest rates that are below each Trust portfolio’s current earnings rate.

Municipal securities are subject to the risk that litigation, legislation or other political events, local business or economic conditions, credit rating downgrades, or the bankruptcy of the issuer could have a significant effect on an issuer’s ability to make payments of principal and/or interest or otherwise affect the value of such securities. Municipal securities can be significantly affected by political or economic changes, including changes made in the law after issuance of the securities, as well as uncertainties in the municipal market related to, taxation, legislative changes or the rights of municipal security holders, including in connection with an issuer insolvency. Municipal securities backed by current or anticipated revenues from a specific project or specific assets can be negatively affected by the discontinuance of the tax benefits supporting the project or assets or the inability to collect revenues for the project or from the assets. Municipal securities may be less liquid than taxable bonds, and there may be less publicly available information on the financial condition of municipal security issuers than for issuers of other securities.

Infectious Illness Risk: An outbreak of an infectious illness, such as the COVID‑19 pandemic, may adversely impact the economies of many nations and the global economy, and may impact individual issuers and capital markets in ways that cannot be foreseen. An infectious illness outbreak may result in, among other things, closed international borders, prolonged quarantines, supply chain disruptions, market volatility or disruptions and other significant economic, social and political impacts.

Counterparty Credit Risk: The Trusts may be exposed to counterparty credit risk, or the risk that an entity may fail to or be unable to perform on its commitments related to unsettled or open transactions, including making timely interest and/or principal payments or otherwise honoring its obligations. The Trusts manage counterparty credit risk by entering into transactions only with counterparties that the Manager believes have the financial resources to honor their obligations and by monitoring the financial stability of those counterparties. Financial assets, which potentially expose the Trusts to market, issuer and counterparty credit risks, consist principally of financial instruments and receivables due from counterparties. The extent of the Trusts’ exposure to market, issuer and counterparty credit risks with respect to these financial assets is approximately their value recorded in the Statements of Assets and Liabilities, less any collateral held by the Trusts.

A derivative contract may suffer a mark‑to‑market loss if the value of the contract decreases due to an unfavorable change in the market rates or values of the underlying instrument. Losses can also occur if the counterparty does not perform under the contract.

With exchange-traded futures, there is less counterparty credit risk to the Trusts since the exchange or clearinghouse, as counterparty to such instruments, guarantees against a possible default. The clearinghouse stands between the buyer and the seller of the contract; therefore, credit risk is limited to failure of the clearinghouse. While offset rights may exist under applicable law, a Trust does not have a contractual right of offset against a clearing broker or clearinghouse in the event of a default (including the bankruptcy or insolvency). Additionally, credit risk exists in exchange-traded futures with respect to initial and variation margin that is held in a clearing broker’s customer accounts. While

clearing brokers are required to segregate customer margin from their own assets, in the event that a clearing broker becomes insolvent or goes into bankruptcy and at that time there is a shortfall in the aggregate amount of margin held by the clearing broker for all its clients, typically the shortfall would be allocated on a pro rata basis across all the clearing broker’s customers, potentially resulting in losses to the Trusts.

Concentration Risk: A diversified portfolio, where this is appropriate and consistent with a fund’s objectives, minimizes the risk that a price change of a particular investment will have a material impact on the NAV of a fund. The investment concentrations within each Trust’s portfolio are disclosed in its Schedule of Investments.

The Trusts invest a significant portion of their assets in fixed-income securities and/or use derivatives tied to the fixed-income markets. Changes in market interest rates or economic conditions may affect the value and/or liquidity of such investments. Interest rate risk is the risk that prices of bonds and other fixed-income securities will decrease as interest rates rise and increase as interest rates fall. The Trusts may be subject to a greater risk of rising interest rates due to the recent period of historically low interest rates. The Federal Reserve has recently begun to raise the federal funds rate as part of its efforts to address inflation. There is a risk that interest rates will continue to rise, which will likely drive down the prices of bonds and other fixed-income securities, and could negatively impact the Trusts’ performance.

LIBOR Transition Risk: The United Kingdom’s Financial Conduct Authority announced a phase out of the London Interbank Offered Rate (“LIBOR”). Although many LIBOR rates ceased to be published or no longer are representative of the underlying market they seek to measure after December 31, 2021, a selection of widely used USD LIBOR rates will continue to be published through June 2023 in order to assist with the transition. The Trusts may be exposed to financial instruments tied to LIBOR to determine payment obligations, financing terms, hedging strategies or investment value. The transition process away from LIBOR might lead to increased volatility and illiquidity in markets for, and reduce the effectiveness of new hedges placed against instruments whose terms currently include LIBOR. The ultimate effect of the LIBOR transition process on the Trusts is uncertain.

Capital Stock [Table Text Block]

10.	CAPITAL SHARE TRANSACTIONS

Redemption Terms: Each VMTP Trust is required to redeem its VMTP Shares on the term redemption date, unless earlier redeemed or repurchased or unless extended. There is no assurance that a term will be extended further or that any VMTP Shares will be replaced with any other preferred shares or other form of leverage upon the redemption or repurchase of the VMTP Shares. Six months prior to the term redemption date, a VMTP Trust is required to begin to segregate liquid assets with its custodian to fund the redemption. In addition, a VMTP Trust is required to redeem certain of its outstanding VMTP Shares if it fails to comply with certain asset coverage, basic maintenance amount or leverage requirements.

Subject to certain conditions, VMTP Shares may be redeemed, in whole or in part, at any time at the option of the VMTP Trust. With respect to each VMTP Trust, the redemption price per VMTP Share is equal to the liquidation preference per share plus any outstanding unpaid dividends and applicable redemption premium. If each VMTP Trust redeems the VMTP Shares prior to the term redemption date and the VMTP Shares have long-term ratings above A1/A+ or its equivalent by the ratings agencies then rating the VMTP Shares, then such redemption may be subject to a prescribed redemption premium (up to 1% of the liquidation preference) payable to the holder of the VMTP Shares based on the time remaining until the term redemption date, subject to certain exceptions for redemptions that are required to comply with minimum asset coverage requirements.

Dividends: Dividends on the VMTP Shares are declared daily and payable monthly at a variable rate set weekly at a fixed rate spread to the Securities Industry and Financial Markets Association (“SIFMA”) Municipal Swap Index or to a percentage of the daily Secured Overnight Financing Rate, as set forth in the VMTP Shares governing instrument. The fixed spread is determined based on the long-term preferred share rating assigned to the VMTP Shares by the ratings agencies then rating the VMTP Shares.

The dividend rate on VMTP Shares is subject to a step‑up spread if the VMTP Trust fails to comply with certain provisions, including, among other things, the timely payment of dividends, redemptions or gross‑up payments, and complying with certain asset coverage and leverage requirements.

Security Voting Rights [Text Block]

Holders of Preferred Shares have voting rights equal to the voting rights of holders of Common Shares (one vote per share) and vote together with holders of Common Shares (one vote per share) as a single class on certain matters. Holders of Preferred Shares, voting as a separate class, are also entitled to (i) elect two members of the Board, (ii) elect the full Board if dividends on the Preferred Shares are not paid for a period of two years and (iii) a separate class vote to amend the Preferred Share governing documents. In addition, the 1940 Act requires the approval of the holders of a majority of any outstanding Preferred Shares, voting as a separate class, to (a) adopt any plan of reorganization that would adversely affect the Preferred Shares, (b) change a Trust’s sub‑classification as a closed‑end investment company or change its fundamental investment restrictions or (c) change its business so as to cease to be an investment company.

Preferred Stock Restrictions, Arrearage [Text Block]

The 1940 Act prohibits the declaration of any dividend on Common Shares or the repurchase of Common Shares if the Trust fails to maintain asset coverage of at least 200% of the liquidation preference of the Trust’s outstanding Preferred Shares. In addition, pursuant to the Preferred Shares’ governing instruments, a Trust is restricted from declaring and paying dividends on classes of shares ranking junior to or on parity with its Preferred Shares or repurchasing such shares if the Trust fails to declare and pay dividends on the Preferred Shares, redeem any Preferred Shares required to be redeemed under the Preferred Shares’ governing instruments or comply with the basic maintenance amount requirement of the ratings agencies rating the Preferred Shares.

Risk [Text Block]

Market Risk: Each Trust may be exposed to prepayment risk, which is the risk that borrowers may exercise their option to prepay principal earlier than scheduled during periods of declining interest rates, which would force each Trust to reinvest in lower yielding securities. Each Trust may also be exposed to reinvestment risk, which is the risk that income from each Trust’s portfolio will decline if each Trust invests the proceeds from matured, traded or called fixed-income securities at market interest rates that are below each Trust portfolio’s current earnings rate.

Municipal securities are subject to the risk that litigation, legislation or other political events, local business or economic conditions, credit rating downgrades, or the bankruptcy of the issuer could have a significant effect on an issuer’s ability to make payments of principal and/or interest or otherwise affect the value of such securities. Municipal securities can be significantly affected by political or economic changes, including changes made in the law after issuance of the securities, as well as uncertainties in the municipal market related to, taxation, legislative changes or the rights of municipal security holders, including in connection with an issuer insolvency. Municipal securities backed by current or anticipated revenues from a specific project or specific assets can be negatively affected by the discontinuance of the tax benefits supporting the project or assets or the inability to collect revenues for the project or from the assets. Municipal securities may be less liquid than taxable bonds, and there may be less publicly available information on the financial condition of municipal security issuers than for issuers of other securities.

General Description of Registrant [Abstract]

Risk [Text Block]

Counterparty Credit Risk: The Trusts may be exposed to counterparty credit risk, or the risk that an entity may fail to or be unable to perform on its commitments related to unsettled or open transactions, including making timely interest and/or principal payments or otherwise honoring its obligations. The Trusts manage counterparty credit risk by entering into transactions only with counterparties that the Manager believes have the financial resources to honor their obligations and by monitoring the financial stability of those counterparties. Financial assets, which potentially expose the Trusts to market, issuer and counterparty credit risks, consist principally of financial instruments and receivables due from counterparties. The extent of the Trusts’ exposure to market, issuer and counterparty credit risks with respect to these financial assets is approximately their value recorded in the Statements of Assets and Liabilities, less any collateral held by the Trusts.

A derivative contract may suffer a mark‑to‑market loss if the value of the contract decreases due to an unfavorable change in the market rates or values of the underlying instrument. Losses can also occur if the counterparty does not perform under the contract.

With exchange-traded futures, there is less counterparty credit risk to the Trusts since the exchange or clearinghouse, as counterparty to such instruments, guarantees against a possible default. The clearinghouse stands between the buyer and the seller of the contract; therefore, credit risk is limited to failure of the clearinghouse. While offset rights may exist under applicable law, a Trust does not have a contractual right of offset against a clearing broker or clearinghouse in the event of a default (including the bankruptcy or insolvency). Additionally, credit risk exists in exchange-traded futures with respect to initial and variation margin that is held in a clearing broker’s customer accounts. While

clearing brokers are required to segregate customer margin from their own assets, in the event that a clearing broker becomes insolvent or goes into bankruptcy and at that time there is a shortfall in the aggregate amount of margin held by the clearing broker for all its clients, typically the shortfall would be allocated on a pro rata basis across all the clearing broker’s customers, potentially resulting in losses to the Trusts.

General Description of Registrant [Abstract]

Risk [Text Block]

LIBOR Transition Risk: The United Kingdom’s Financial Conduct Authority announced a phase out of the London Interbank Offered Rate (“LIBOR”). Although many LIBOR rates ceased to be published or no longer are representative of the underlying market they seek to measure after December 31, 2021, a selection of widely used USD LIBOR rates will continue to be published through June 2023 in order to assist with the transition. The Trusts may be exposed to financial instruments tied to LIBOR to determine payment obligations, financing terms, hedging strategies or investment value. The transition process away from LIBOR might lead to increased volatility and illiquidity in markets for, and reduce the effectiveness of new hedges placed against instruments whose terms currently include LIBOR. The ultimate effect of the LIBOR transition process on the Trusts is uncertain.

Capital Stock, Long-Term Debt, and Other Securities [Abstract]

Outstanding Security, Held [Shares]

3,027

Capital Stock, Long-Term Debt, and Other Securities [Abstract]

Outstanding Security, Held [Shares]

48,775,792