白石信托美股招股说明书(2025-09-16版)

(To prospectus dated May 19, 2025) $100,000,000Common Shares We have entered into separate equity distribution agreements dated September 16, 2025, or, the equity distributionagreements, with each of BMO Capital Markets Corp., BarclaysCapital Inc., BofA Securities, Inc., BTIG, LLC, Capital OneSecurities, Inc., Citizens JMP Securities, LLC, Deutsche Bank Securities Inc., Goldman Sachs & Co. LLC, KeyBancCapitalMarkets Inc., RBC Capital Markets, LLC, Robert W. Baird & Co. Incorporated, Truist Securities, Inc., and UBS Securities LLC,each a sales agent and, collectively, the sales agents, relating to our common shares of beneficial interest, par value $0.001 pershare, or our common shares, offered by this prospectus supplement and the accompanying prospectus. In accordance with theterms of the equity distribution agreements, we may from time to time offer and sell common shares having an aggregateoffering price of up to $100,000,000 through the sales agents, as our agents. Sales of our common shares, if any, pursuant to this prospectus supplement and the accompanying prospectus may bemade in negotiated transactions or transactions that are deemed to be “at the market” offerings as defined in Rule 415 under theSecurities Act of 1933, as amended, or the Securities Act, including, without limitation, sales made by means of ordinary brokers’transactions, including directly on the New York Stock Exchange, or the NYSE, in privately negotiated transactions (includingblock transactions) or sales made to or through a market maker other than on an exchange. The sales agents are not required to sellany specific number or dollar amount of our common shares, but as instructed by us will make all sales using commerciallyreasonable efforts, consistent with their normal trading and sales practices, as our sales agents and subject to the terms of the equitydistribution agreements. From time to time during the terms of the equity distribution agreements, we may deliver a placementnotice to one of the sales agents specifying the length of the selling period, the amount of shares to be sold and the minimum pricebelow which sales may not be made. Our common shares to which this prospectus supplement relates will be sold only throughone sales agent on any given day. The offering of common shares pursuant to the equity distribution agreements will terminateupon the earlier of (1) the sale of our common shares having an aggregate offering price of $100,000,000 or (2) the termination ofthe equity distribution agreements. The common shares to which this prospectus supplement relates will be offered and sold at prevailing market prices or atnegotiated prices through the sales agents over a period of time and from time to time in transactions at then-current prices. Eachsales agent will be entitled to compensation that will not exceed 2.0% of the gross sales price per share for any common sharessold through it. In connection with the sale of common shares on our behalf, the sales agents may be deemed to be “underwriters”within the meaning of the Securities Act, and the compensation of the sales agents may be deemed to be underwriting discounts orcommissions. Under the terms of the equity distribution agreements, we also may sell shares to each of the sales agents, as principal forits own respective account, at a price agreed upon at the time of sale. If we sell shares to a sales agent as principal, we will enterinto a separate agreement with the sales agent, setting forth the terms of such transaction, and we will describe the agreement in aseparate prospectus supplement or pricing supplement. Our common shares are listed on the NYSE under the symbol “WSR.” On September 15, 2025, the last reported saleprice of our common shares on the NYSE was $12.93per share. We are organized and conduct our operations to qualify as a real estate investment trust, or REIT, for U.S. federal incometax purposes. To assist us in complying with certain U.S. federal income tax requirements applicable to REITs, among otherpurposes, our declaration of trust contains certain restrictions relating to the ownership and transfer of our common shares,including an ownership limit of 9.8% (in value or number of shares, whichever is more restrictive) of our outstanding commonshares. See “Description of Shares − Restrictions on Ownership and Transfer” in the accompanying prospectus. Investing in our common shares involves risks. See“Risk Factors”beginning on page S-4 of this prospectus supplementand the risk factors discussed in our most recent Annual Report on Form 10-K and in our other periodic reports filed withthe Securities and Exchange Commission and incorporated herein by reference. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved ofthese securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Anyrepresentation to the contrary is a criminal