$300,000,000

Common Stock

Preferred Stock

Depositary Shares

Debt Securities

Guarantees of Debt Securities

Warrants

Units

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This prospectus relates to the offer and sale from time to time in one or more offerings by us of an indeterminate amount of the securities identified above, at an aggregate offering price not to exceed $300,000,000. We refer to the common stock, preferred stock, depositary shares, debt securities, guarantees of debt securities, warrants and units collectively as the "securities." We will offer the securities in amounts, at prices and on terms to be determined by market conditions at the time of the offerings. The debt securities we may offer may be guaranteed by certain of our subsidiaries. We may also offer securities issuable upon conversion, redemption, repurchase, exercise or exchange of, or the payment of interest or dividends on, securities offered hereunder. The securities may be offered separately or together in any combination or as a separate series.

 

This prospectus provides you with a general description of the securities that may be offered. Each time securities are offered, we will provide a prospectus supplement and attach it to this prospectus. The prospectus supplement will contain more specific information about the offering and the terms of the securities being offered. The supplement may also add, update or change information contained in this prospectus. This prospectus may not be used to offer or sell securities without a prospectus supplement describing the method and terms of the offering.

 

We may sell these securities on a continuous or delayed basis directly or through agents, underwriters or dealers, or through a combination of these methods. See "Plan of Distribution." The prospectus supplement will list any agents, underwriters or dealers that may be involved, the compensation they will receive and the nature of any underwriting or similar agreement. The prospectus supplement will also describe the total amount of money that we will receive from selling the securities being offered, after the expenses of the offering, and the price of the securities being offered. You should read carefully this prospectus and any accompanying prospectus supplement, together with the documents we incorporate by reference, before you invest in any of our securities.

 

Our common stock is listed on the New York Stock Exchange (the "NYSE") under the symbol "ALTG" and depositary shares representing a 1/1000th fractional interest in a share of our 10% Series A Cumulative Perpetual Preferred Stock are listed on the NYSE under the symbol "ALTG PRA". On April 30, 2026, the last reported sale price for our common stock and depositary shares was $7.75 and $25.14 per share, respectively. We have not yet determined whether other securities that may be offered by this prospectus will be listed on any exchange, interdealer quotation system or over-the-counter market. If we decide to seek the listing of any such securities upon issuance, the prospectus supplement relating to those securities will disclose the exchange, quotation system or market on which those securities will be listed.