忠实航空美股招股说明书(2026-03-31版)

TRANSACTION PROPOSED-YOUR VOTE IS VERY IMPORTANT Dear Stockholders of Allegiant and Sun Country: On behalf of the boards of directors of Allegiant Travel Company (which we refer to as Allegiant) and Sun Country Airlines Holdings, Inc. (which we refer to asSunCountry), we are pleased to enclose the accompanying joint proxy statement/prospectus relating to the proposed acquisition of Sun Country by Allegiant. Weare requesting that you take certain actions as a holder of Allegiant common stock or Sun Country common stock, as more fully described in this joint proxystatement/prospectus. Each of the boards of directors of Allegiant and Sun Country has unanimously approved or adopted, as applicable, an Agreement and Plan of Merger, dated as ofJanuary11, 2026 (which agreement, as it may be amended from time to time, we refer to as the merger agreement), by and among Allegiant, Mirage Merger Sub,Inc., a direct, wholly owned subsidiary of Allegiant (which we refer to as Merger Sub 1), Sawdust Merger Sub, LLC, a direct, wholly owned subsidiary of Allegiant(which we refer to as Merger Sub 2) and Sun Country. Subject to the terms and conditions of the merger agreement, which are more fully described in theaccompanying joint proxy statement/prospectus, Allegiant will acquire Sun Country through the merger of Merger Sub 1 with and into Sun Country (whichtransaction we refer to as the first merger). Sun Country will survive the first merger and become a direct, wholly owned subsidiary of Allegiant. In addition, asmore fully described in the accompanying joint proxy statement/prospectus, immediately following the completion of the first merger, Sun Country will merge withand into Merger Sub 2, with Merger Sub2surviving as a direct, wholly owned subsidiary of Allegiant (which transaction we refer to as the second merger and,together with the first merger, the mergers). If the first merger is completed, Sun Country stockholders will be entitled to receive (i) 0.1557 (which we refer to as the exchange ratio) shares of Allegiant commonstock (which we refer to as the per-share stock consideration) and (ii) $4.10 in cash, without interest (which we refer to as the per-share cash consideration) for eachshare of Sun Country common stock that they hold immediately prior to the completion of the first merger. We refer to the per-share stock consideration and the per-share cash consideration collectively as the merger consideration. The exchange ratio is fixed and will not be adjusted to reflect stock price changes prior to theconsummation of the first merger. Allegiant stockholders will continue to own their existing shares of common stock of Allegiant, the form of which will not bechanged by the transaction. Upon closing, former Sun Country equityholders will represent approximately 33% of Allegiant common stock on a fully diluted basis and Allegiant equityholderswill represent approximately the remaining 67%, calculated on a fully diluted basis, based on the number of shares of common stock and stock-based awards ofAllegiant and Sun Country outstanding as of March26, 2026, the last practicable trading day before the date of the accompanying joint proxy statement/prospectus. The value of the merger consideration to be received in exchange for each share of Sun Country common stock will fluctuate with the market value of Allegiantcommon stock until the first merger is completed. Based on Allegiant’s closing share price on January 9, 2026, the implied value of the merger consideration was$18.89, which represents a premium of approximately 19.8% over Sun Country’s closing share price on January 9, 2026, and 18.8% over the 30-day volume-weighted average closing price. Based on Allegiant’s closing share price on March26, 2026, the last practicable trading day before the date of the accompanyingjoint proxy statement/prospectus, the implied value of the merger consideration was $17.17. The common stock of each of Allegiant and Sun Country is listed onNasdaq under the symbol “ALGT” and “SNCY,” respectively. We urge you to obtain current market quotations for the shares of common stock of Allegiant and SunCountry. Each of Allegiant and Sun Country will hold a special meeting of its stockholders in connection with the mergers, the issuance of Allegiant common stock inconnection with the first merger, and the other transactions contemplated by the merger agreement (which we refer to as the proposed transactions). Allegiant’s special meeting of stockholders will be held at Allegiant’s headquarters at 1201 N. Town Center Drive, Las Vegas, Nevada 89144 on May8, 2026 at 9:00a.m., Pacific Time (unless it is adjourned or postponed to a later date). At the Allegiant special meeting, Allegiant stockholders will be asked to consider and vote onthe following matters: (i) a proposal to approve the issuance of Allegiant common stock in connection with the first merger (which we refer to as the share issuanceproposal) and (ii) a proposal to give t