Company: PTY
Filing Date: 2025-06-06
Form Type: 424B5
Source: 0001193125-25-137029
Chunk: 291

Company: PIMCO CORPORATE & INCOME OPPORTUNITY FUND
Filing Date: 2025-06-06
Form: 424B5
Chunk 291
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or pays. Therefore, if current interest rates rise above such limits over the period of the limitation, the Fund, when holding an ARMBS, does not benefit from further increases in interest rates. Moreover, when interest rates are in excess of coupon rates (i.e., the rates being paid by mortgagors) of the mortgages, ARMBSs behave more like fixed income securities and less like adjustable rate securities and are subject to the risks associated with fixed income securities. In addition, during periods of rising interest rates, increases in the coupon rate of adjustable rate mortgages generally lag current market interest rates slightly, thereby creating the potential for capital depreciation on such securities. Stripped Mortgage-Backed Securities. SMBS are derivative multi-class mortgage securities. SMBS may be issued by agencies or instrumentalities of the U.S. government, or by private originators of, or investors in, mortgage

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loans, including savings and loan associations, mortgage banks, commercial banks, investment banks and special purpose entities of the foregoing. SMBS are usually structured with two classes that receive different proportions of the interest and principal distributions on a pool of mortgage assets. A common type of SMBS will have one class receiving some of the interest and most of the principal from the mortgage assets, while the other class will receive most of the interest and the remainder of the principal. In the most extreme case, one class will receive all of the interest (the “IO” class), while the other class will receive all of the principal (the “PO” class). The yield to maturity on an IO class is extremely sensitive to the rate of principal payments (including prepayments) on the related underlying mortgage assets, and a rapid rate of principal payments may have a material adverse effect on the Fund’s yield to maturity from these securities. If the underlying mortgage assets experience greater than anticipated prepayments of principal, the Fund may fail to recoup some or all of its initial investment in these securities even if the security is in one of the highest rating categories. SMBSs may be deemed “illiquid.” Other Mortgage-Related Securities. Other mortgage-related securities include securities other than those described above that directly or indirectly represent a participation in, or are secured by and payable from, mortgage loans on real property, including mortgage dollar rolls/buy backs, CMO residuals or SMBSs. Other mortgage-related securities may be equity or debt securities issued by agencies or instrumentalities of the U.S. government or by private originators of, or investors in, mortgage loans, including