阿曼瑞恩美股招股说明书(2025-05-13版)

The forward sellers referred to below are offering 5,550,416 shares of our common stock, $.01 par value per share. We have entered into forward saleagreements with each of Goldman Sachs & Co. LLC, JPMorgan Chase Bank, National Association, Barclays Bank PLC and Wells Fargo Bank, NationalAssociation, whom we refer to in such capacity as the “forward purchasers,” with respect to an aggregate of 5,550,416 shares of our common stock. Inconnection with these forward sale agreements, the forward purchasers or their affiliates and/or agents, whom we refer to in such capacity as the “forwardsellers,” at our request, are borrowing from third parties and selling to the underwriters an aggregate of 5,550,416 shares of our common stock. If in the goodfaith, commercially reasonable judgment of a forward purchaser, it or its affiliate is unable to borrow and deliver for sale on the anticipated closing date anumber of shares of our common stock underlying its forward sale agreement, or it or its affiliate would be unable to borrow, at a stock loan rate not greater thana specified rate, and deliver for sale on the anticipated closing date such number of shares of our common stock, or if certain other conditions to such forwardseller’s obligations have not been satisfied, then we will issue and sell directly to the underwriters a number of shares of our common stock equal to the numberof shares that such forward seller does not borrow and deliver. We will not initially receive any proceeds from the sale of the shares of our common stock sold by the forward sellers to the underwriters, except in certaincircumstances described in this prospectus supplement, including the last sentence of the previous paragraph. Each forward sale agreement provides forsettlement on a settlement date or dates to be specified at our discretion on or prior to January 15, 2027. If we elect to cash settle all or a portion of the forwardsale agreements, we may not receive any proceeds from such election, and we may owe cash to one or more of the forward purchasers. If we elect to net sharesettle all or a portion of the forward sale agreements, we will not receive any cash proceeds from such election, and we may owe shares of our common stock toone or more of the forward purchasers. See “Underwriting (Conflicts of Interest) — Forward Sale Agreements” for a description of the forward sale agreements. Our common stock is listed on the New York Stock Exchange, or the NYSE, under the symbol “AEE.” The last reported sale price of our common stockon May12, 2025 was $95.42 per share. Investing in our common stock involves risks. See “Risk Factors” beginning on pageS-8of this prospectus supplement. Neither the Securities and Exchange Commission nor any other regulatory body has approved or disapproved of these securities or passed upon the accuracy oradequacy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense. (1)We expect to receive net proceeds, before expenses, from the sale of our common stock of approximately $510.0 million (or approximately $586.5 millionif the underwriters’ option to purchase additional shares of our common stock is exercised in full, as described in detail below) upon full physicalsettlement of the forward sale agreements, which we expect to occur on or prior to January 15, 2027. For purposes of calculating the estimated netproceeds to us, we have assumed that the forward sale agreements are fully physically settled based on the initial forward sale price of $91.885 per share,which is equal to the offering price per share less the underwriting discount shown above. The forward sale price is subject to adjustment pursuant to theforward sale agreements, and the actual proceeds, if any, will be calculated as described in this prospectus supplement. Although we expect to settle theforward sale agreements entirely by the full physical delivery of shares of our common stock to the forward purchasers in exchange for cash proceeds, wemay elect cash settlement or net share settlement for all or a portion of our obligations under one or more forward sale agreements, in which case we mayreceive no cash proceeds or substantially less cash proceeds than is reflected in the above table upon settlement, or we may be required to deliver cash orshares of our common stock to the forward purchasers. See “Underwriting (Conflicts of Interest)— Forward Sale Agreements” for a description of theforward sale agreements. We have granted the underwriters an option for a period of 30days from the date of this prospectus supplement to purchase up to an additional 832,562shares of our common stock at a price of $91.885 per share. If such option is exercised, we may, in our sole discretion, enter into additional forward saleagreements with each of the forward purchasers in respect of the number of shares of our common stock that are subject to the exercise of such option. Unlessthe context r