Definitive Materials Filed by Investment Companies. (497)

Effective immediately, the sub-section entitled "Valuation" beneath the main heading "Other Information" is restated in its entirety as follows:

Valuation

The price of each class of the fund’s shares is based on its net asset value. The net asset value of each class of shares is determined each day the NYSE is open for trading as of the close of regular trading on the NYSE (generally 4:00 p.m. Eastern time). However, net asset value may be calculated earlier in emergency situations or as otherwise permitted by the SEC. Net asset value per share is computed by dividing the net assets allocated to each share class by the number of shares outstanding for that class. On days when the NYSE is closed (such as weekends and holidays), net asset value is not calculated, and the fund does not transact purchase and redemption orders. To the extent the fund’s assets are traded in other markets on days when the fund does not price its shares, the value of the fund's assets will likely change when you will not be able to purchase or redeem shares of the fund.

To determine net asset value, the fund’s investments for which reliable market quotations are readily available are valued at market value. Certain short term debt instruments are valued at amortized cost.

The Board of Trustees has delegated primary responsibility for determining or causing to be determined the value of the fund’s investments (including any fair valuation) to the adviser pursuant to valuation policies and procedures approved by the Board. If the adviser determines that reliable market quotations are not readily available, investments are valued at fair value as determined in good faith by the adviser in accordance with such procedures under the oversight of the Board of Trustees.

Under the fund’s valuation policies and procedures, market quotations are not considered to be readily available for most types of debt instruments and many types of derivatives. These investments are generally valued at fair value based on information from third-party pricing services. These valuations can be based on both transaction data and market information such as yield, quality, coupon rate, maturity, type of issue, trading characteristics, and other market data.

In addition, investments may be valued at fair value if the adviser determines that an investment’s value has been materially affected by events occurring after the close of the exchange or market on which the investment is principally traded (such as a foreign exchange or market) and prior to the determination of the fund’s net asset value, or after the halting of trading of a specific security where trading does not resume prior to the close of the exchange or market on which the security is principally traded. The adviser generally relies on third-party pricing services or other information (such as the correlation with price movements of similar securities in the same or other markets; the type, cost and investment characteristics of the security; the business and financial condition of the issuer; and trading and other market data) to assist in determining whether to fair value and at what value to fair value an investment. The value of an investment for purposes of calculating the fund’s net asset value can differ depending on the source and method used to determine value. When fair valuation is used, the value of an investment used to determine the fund’s net asset value may differ from quoted or published prices for the same investment. There can be no assurance that the fund could obtain the fair value assigned to an investment if it were to sell the investment at the same time at which the fund determines its net asset value per share.

223882 1 IAB-OTHR-SUP-072913