A. Security Valuation: Securities are valued as of the close of trading on the New York Stock Exchange (generally 4 p.m., Eastern time) on the valuation date. Bonds and other temporary cash investments are valued using the latest bid prices or using valuations based on a matrix system (which considers such factors as security prices, yields, maturities, and ratings), both as furnished by independent pricing services. Structured debt securities, including mortgages and asset-backed securities, are valued using the latest bid prices or using valuations based on a matrix system that considers such factors as issuer, tranche, nominal or option-adjusted spreads, weighted average coupon, weighted average maturity, credit enhancements, and collateral, as furnished by independent pricing services. Investments in Vanguard Market Liquidity Fund are valued at that fund's net asset value. Securities for which market quotations are not readily available, or whose values have been affected by events occurring before the fund's pricing time but after the close of the securities’ primary markets, are valued by methods deemed by the valuation designee to represent fair value and subject to oversight by the board of trustees.
B. Foreign Currency: Securities and other assets and liabilities denominated in foreign currencies are translated into U.S. dollars using exchange rates obtained from an independent third party as of the fund’s pricing time on the valuation date. Realized gains (losses) and unrealized appreciation (depreciation) on investment securities include the effects of changes in exchange rates since the securities were purchased, combined with the effects of changes in security prices. Fluctuations in the value of other assets and liabilities resulting from changes in exchange rates are recorded as unrealized foreign currency gains (losses) until the assets or liabilities are settled in cash, at which time they are recorded as realized foreign currency gains (losses).
C. To Be Announced (TBA) Transactions: A TBA transaction is an agreement to buy or sell mortgage-backed securities with agreed-upon characteristics (face amount, coupon, maturity) for settlement at a future date. The fund may be a seller of TBA transactions to reduce its exposure to the mortgage-backed securities market or in order to sell mortgage-backed securities it owns under delayed-delivery arrangements. When the fund is a buyer of TBA transactions, it maintains cash or short-term investments in an amount sufficient to meet the purchase price at the settlement date of the TBA transaction. The primary risk associated with TBA transactions is that a counterparty may default on its obligations. The fund mitigates its counterparty risk by, among other things, performing a credit analysis of counterparties, allocating transactions among numerous counterparties, and monitoring its exposure to each counterparty. The fund may also enter into a Master Securities Forward Transaction Agreement (MSFTA) with certain counterparties and require them to transfer collateral as security for their performance. In the absence of a default, the collateral pledged or received by the fund cannot be repledged, resold, or rehypothecated. Under an MSFTA, upon a counterparty default (including bankruptcy), the fund may terminate any TBA transactions with that counterparty, determine the net amount owed by either party in accordance with its MSFTA, and sell or retain any collateral held up to the net amount owed to the fund under the MSFTA.
D. Floating Rate Loan Interests: Floating rate loan interests represent interests in amounts owed by corporate or other borrowers. These instruments may be in the form of loans, trade claims or other receivables and may include standby financing commitments such as revolving credit facilities that obligate the fund to supply additional cash to the borrower on demand. Floating rate loan interests may be made directly with a borrower or acquired through assignment or participation. The fund's right to enforce a borrower’s compliance with the terms of the loan agreement, or benefit directly from the collateral supporting the loan, varies when the loan is a direct borrowing, an assignment, or a participation. Floating rate loan interests involve various risks including risk of loss in case of default, insolvency, or the bankruptcy of the borrower and are generally subject to restrictions on transfer with limited opportunities to sell them in secondary markets. The fund may also invest in loan commitments, which are contractual obligations for a future funding. The fund may earn a commitment fee on any unfunded portion of these commitments which is amortized to interest income over the commitment period. Both the funded portion of a floating rate loan interest as well as its unfunded commitment, if any, is reflected on the Schedule of Investments.
