Waystar Holding Corp美股招股说明书(2025-09-11版)

Common Stock This is a public offering of 18,000,000 shares of common stock of Waystar Holding Corp. The sellingstockholders identified in this prospectus supplement are offering 18,000,000 shares of common stock. Weare not selling any shares of common stock under this prospectus supplement and will not receive anyproceeds from the sale of the shares by the selling stockholders. Our common stock is listed on the Nasdaq Global Select Market (“Nasdaq”) under the symbol “WAY.”On September 10, 2025, the last reported sale price of our common stock on Nasdaq was $40.50 per share. Investing in our common stock involves risks. See “Risk Factors” beginning on pageS-5of this prospectussupplement and in the reports we file with the U.S. Securities and Exchange Commission (the “SEC”) pursuant tothe Securities Exchange Act of 1934, as amended (the “Exchange Act”), incorporated by reference in thisprospectus supplement or the accompanying prospectus, to read about factors you should consider before buyingshares of our common stock. Neither the SEC nor any state securities commission has approved or disapproved of these securities orpassed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Anyrepresentation to the contrary is a criminal offense. Per ShareTotalPublic offering price$39.40$709,200,000Underwriting discount$0.19$3,420,000Proceeds, before expenses, to the selling stockholders$39.21$705,780,000(1) (1)See “Underwriting” for a description of the compensation payable to the underwriter. The underwriter expects to deliver the shares against payment in New York, New York on or aboutSeptember 12, 2025. J.P. Morgan Prospectus Supplement dated September 10, 2025. TABLE OF CONTENTS Prospectus Supplement PageProspectus Supplement SummaryS-1Risk FactorsS-5Special Note Regarding Forward-Looking StatementsS-11Use of ProceedsS-14Selling StockholdersS-15UnderwritingS-17Legal MattersS-25ExpertsS-25Where You Can Find More InformationS-25Incorporation by ReferenceS-25 Prospectus PageProspectus Summary1Risk Factors6Special Note Regarding Forward-Looking Statements7Use of Proceeds10Selling Stockholders11Description of Capital Stock13Certain United States Federal Income Tax Consequences to Non-U.S. Holders22Plan of Distribution25Legal Matters27Experts27Where You Can Find More Information28Information Incorporated by Reference28 You should rely only on the information contained or incorporated by reference in this prospectussupplement and the accompanying prospectus or any free writing prospectus we may authorize to be deliveredor made available to you. Neither we nor the selling stockholders or the underwriter have authorized anyone toprovide you with information or to make any representations different from those contained or incorporated byreference in this prospectus supplement and the accompanying prospectus or any free writing prospectusprepared by us or on our behalf. Neither we nor the selling stockholders or the underwriter take anyresponsibility for, or can provide any assurance as to the reliability of, any information other than theinformation contained or incorporated by reference in this prospectus supplement and the accompanyingprospectus or any free writing prospectus prepared by us or on our behalf. This prospectus supplement and theaccompanying prospectus or any applicable free writing prospectus is an offer to sell only the shares of commonstock offered hereby, but only under circumstances where it is lawful to do so. The selling stockholders and theunderwriter are not offering to sell shares of our common stock in any jurisdiction where an offer or sale is notpermitted. The information contained in or incorporated by reference in this prospectus supplement and theaccompanying prospectus or any free writing prospectus prepared by us or on our behalf is accurate only as ofthe date of this prospectus supplement, regardless of the time of delivery of this prospectus supplement and theaccompanying prospectus or any applicable free writing prospectus prepared by us or on our behalf or any saleof shares of our common stock. Our business, results of operations, and financial condition may have changedsince such date. For investors outside of the United States, neither we nor the selling stockholders or the underwriterhave done anything that would permit this offering or the possession or distribution of this prospectussupplement and the accompanying prospectus or any applicable free writing prospectus in any jurisdictionwhere action for that purpose is required, other than in the United States. You are required to informyourselves about and to observe any restrictions relating to the offering of shares of common stock and thepossession or distribution of this prospectus supplement and the accompanying prospectus or any applicablefree writing prospectus outside of the United States. About This Prospectus Supplement This document has two parts, a prospectus supplem