Filed Pursuant to Rule 424(b)(3) Registration No. 333-63976 Registration No. 333-67988 Trust Preferred Income Equity Redeemable Securities (PIERS) Units CUSIP No. 939322 84 8 Warrants to purchase shares of Washington Mutual, Inc. Common Stock CUSIP No. 939322 11 1 Trust Preferred Securities issued by Washington Mutual Capital Trust 2001 CUSIP No. 93933U 40 7 PROSPECTUS SUPPLEMENT DATED JANUARY 9, 2002 (TO PROSPECTUS DATED SEPTEMBER 4, 2001) WASHINGTON MUTUAL, INC. Trust Preferred Income Equity Redeemable Securities (PIERS) Units This document supplements the prospectus dated September 4, 2001, relating to the units. Each unit consists of: o a preferred security issued by Washington Mutual Capital Trust 2001 (the "Trust"), having a stated liquidation amount of $50, representing an undivided beneficial interest in the assets of the Trust, which assets consist solely of subordinated debentures issued by Washington Mutual, Inc. each of which has a principal amount at maturity of $50, a stated maturity of July 1, 2041 and, at any time, an accreted value as described in the prospectus; and o a warrant to purchase at any time prior to the close of business on May 3, 2041, 1.2081 shares of common stock of Washington Mutual. The exercise price of each warrant on the initial date of issuance was $32.33 and will accrete on a daily basis as described in the prospectus to $50 on the expiration date. At any time after issuance of the units, the preferred security and warrant components of each unit may be separated by the holder and transferred separately. Thereafter, a separated preferred security and warrant may be combined to form a unit. The information in this prospectus supplements the information set forth under the heading "Selling Securityholders" in the prospectus dated September 4, 2001. McMahan Securities Co. L.P. and Prudential Financial are added to the list of Selling Securityholders, and the number of units that may be sold pursuant to the Registration Statement is as set forth opposite each company's name. Securities Beneficially Owned Prior to the Offering Securities that -------------------------------------- May be Sold Selling Securityholder Number Type Hereunder --------------------------------------- -------------- ----------- ---------------- McMahan Securities Co. L.P. . . . . 300 Units 300 Prudential Financial. . . . . . . . 270 Units 270 ----------- "Preferred Income Equity Redeemable Securities" and "PIERS" are service marks owned by Lehman Brothers Inc. NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED THESE SECURITIES OR DETERMINED IF THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE. THESE SECURITIES OFFERED HEREBY ARE NOT SAVINGS ACCOUNTS, DEPOSITS OR OTHER OBLIGATIONS OF ANY BANK OR SAVINGS ASSOCIATION AND ARE NOT INSURED BY THE FEDERAL DEPOSIT INSURANCE CORPORATION, THE BANK INSURANCE FUND, THE SAVINGS ASSOCIATION INSURANCE FUND OR ANY OTHER GOVERNMENTAL AGENCY. 2