SCHEDULE 13D/A 0001019264 XXXXXXXX LIVE 3 Common Stock, $0.01 par value per share 12/03/2025 false 0001031235 37955N106 GLOBAL SELF STORAGE, INC.

3814 Route 44 Millbrook NY 12545

Donald Klimoski II, Esq. 2127850900 3814 Route 44 Millbrook NY 12545 0001019264 Mark Campbell Winmill AF PF X1 339238.29 608497 339238.29 608497 947735.29 N 8.4 IN Percent of class in Row 13 based on 11,337,720 shares of common stock, $0.01 par value per share outstanding as of November 6, 2025, as reported by Global Self Storage, Inc. (the "Issuer") on its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 7, 2025 0001018500 Thomas Bassett Winmill AF PF X1 1100 586500 1100 586500 587600 N 5.2 IN Percent of class in Row 13 based on 11,337,720 shares of common stock, $0.01 par value per share outstanding as of November 6, 2025, as reported by the Issuer on its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 7, 2025. Y Winmill Family Trust AF X1 0 586500 0 586500 586500 N 5.2 HC Percent of class in Row 13 based on 11,337,720 shares of common stock, $0.01 par value per share outstanding as of November 6, 2025, as reported by the Issuer on its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 7, 2025. 0000052234 Winmill & Co. Incorporated AF WC X1 147641 438859 147641 438859 586500 N 5.2 HC Percent of class in Row 13 based on 11,337,720 shares of common stock, $0.01 par value per share outstanding as of November 6, 2025, as reported by the Issuer on its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 7, 2025. 0001141394 Midas Securities Group, Inc. AF WC X1 135101 303758 135101 303758 438859 N 3.9 BD Percent of class in Row 13 based on 11,337,720 shares of common stock, $0.01 par value per share outstanding as of November 6, 2025, as reported by the Issuer on its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 7, 2025. 0000736952 TUXIS CORP SC WC X1 303758 0 303758 0 303758 N 2.7 CO Percent of class in Row 13 based on 11,337,720 shares of common stock, $0.01 par value per share outstanding as of November 6, 2025, as reported by the Issuer on its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 7, 2025. Common Stock, $0.01 par value per share GLOBAL SELF STORAGE, INC. 3814 Route 44 Millbrook NY 12545 This Amendment Number 3 ("Amendment 3") to the Schedule 13D relates to the shares of common stock, $0.01 par value per share ("Shares") of Global Self Storage, Inc., a Maryland corporation (the "Issuer"). The principal executive offices of the Issuer are located at 3814 Route 44, Millbrook, NY 12545. The Schedule 13D was initially filed with the Securities and Exchange Commission ("SEC") on March 17, 2017, was amended by Amendment Number 1 filed with the SEC on June 1, 2018, and was amended by Amendment Number 2 filed with the SEC on May 21, 2025 (together with the initial Schedule 13D, collectively, ("Schedule 13D"). Except to the extent amended and supplemented by this Amendment 3, the Schedule 13D is not modified. (a) - (c) This Schedule 13D is being filed by the following (collectively, the "Reporting Persons"): Mark C. Winmill 3814 Route 44, Millbrook, NY 12545 Thomas B. Winmill PO Box 4, Walpole, NH 03608 Winmill Family Trust (the "Trust") a New Hampshire trust PO Box 1198, Walpole, NH 03608 Winmill & Co. Incorporated ("Winco") a Delaware corporation Holding company 2255 Buffalo Road, Rochester, NY 14624 Midas Securities Group, Inc. ("MSG") a Delaware corporation Broker/dealer 2255 Buffalo Road, Rochester, NY 14624 Tuxis Corporation ("TUXS") a Maryland corporation Holding company 2255 Buffalo Road, Rochester, NY 14624 Mark C. Winmill has been Chief Executive Officer, President and Chairman of the Board of the Issuer and its subsidiaries since 2012. He is also Chief Executive Officer, President, and a director of TUXS (a holding company) and its subsidiaries. He is Vice President of Foxby Corp. and Midas Series Trust. He is also Vice President of Midas Management Corporation (a registered investment adviser). He is Executive Vice President and a director of Winco. He is a principal of MSG, a registered broker-dealer (the "Broker-Dealer"). Messrs. Mark and Thomas Winmill are brothers. Thomas B. Winmill has served as a director of the Issuer since 1997. He is also President, Chief Executive Officer, Chief Legal Officer, and a director or trustee of Bexil Investment Trust, Foxby Corp., and Midas Series Trust (collectively, the "Funds"). He is President, Chief Executive Officer, Chief Legal Officer, and a director of Bexil Advisers LLC and Midas Management Corporation (registered investment advisers and, collectively, the "Advisers"), the Broker-Dealer, and Bexil Corporation (a holding company) ("Bexil"). He is President, Chief Executive Officer, and Chief Legal Officer of Winco. He is a director of Bexil American Mortgage Inc. ("Bexil American"). Messrs. Mark and Thomas Winmill are brothers. The Funds, the Advisers, Winco, the Broker-Dealer, Bexil, and Bexil American may be deemed to be affiliates of Mark C. Winmill and Thomas B. Winmill. Messrs. Mark and Thomas Winmill are trustees of the Trust. Information required by Instruction C of Schedule 13D with respect to other directors and executive officers of and trustees is attached hereto as Exhibit A, Item 2 and is incorporated herein by reference. See Item 2(a). See Item 2(a). None. None. Mark C. Winmill and Thomas B. Winmill are citizens of the United States of America. Mr. Mark C. Winmill used personal funds to acquire 144,876 directly owned Shares. His Shares also include 182,363 restricted Shares that are subject to restrictions on transfers and forfeiture provisions and were pursuant to restricted stock awards. The forfeiture and transfer restrictions lapse over a four-year period beginning on the date of grant. Mr. Mark Winmill is Chairman of the Board, President, and Chief Executive Officer of TUXS and may be deemed to have indirect beneficial ownership of 303,758 Shares directly owned by TUXS. Mr. Mark Winmill is a trustee of the Winmill Family Trust, which owns all of the voting stock of Winco, and may be deemed to have indirect beneficial ownership of 147,641 Shares directly owned by Winco. Additionally, MSG, a wholly owned subsidiary of Winco, directly owns 135,101 Shares and approximately 19% of TUXS' outstanding shares of common stock and may be deemed to have indirect beneficial ownership of the Shares directly owned by TUXS. Mr. Mark Winmill also is a trustee of the Michael M. George Trust and may be deemed to have indirect beneficial ownership of 21,997 Shares directly owned by the Michael M. George Trust. Mr. Mark Winmill disclaims beneficial ownership of the Shares owned, or which may be deemed to be owned, by TUXS, the Trust, Winco, MSG, and the Michael M. George Trust. Mr. Thomas B. Winmill used personal funds to acquire 1,100 directly owned Shares. Mr. Thomas Winmill is a trustee of the Trust and may be deemed to have indirect beneficial ownership of the 586,500 Shares directly and indirectly owned by Winco as a result of his status as a controlling person of the Trust. Mr. Thomas Winmill disclaims beneficial ownership of the Shares owned, or which may be deemed to be owned, by TUXS, the Trust, Winco, and MSG. Winco has direct beneficial ownership of 147,641 Shares and may be deemed to have indirect beneficial ownership of 303,758 Shares held by TUXS. MSG directly owns 135,101 Shares and approximately 19% of TUXS' outstanding shares of common stock and may be deemed to have indirect beneficial ownership of the Shares directly owned by TUXS. Winco disclaims beneficial ownership of the 303,758 Shares held by TUXS. Winco used working capital to acquire Shares. The Trust owns all of the voting stock of Winco. TUXS directly owns 303,758 Shares. TUXS used working capital to acquire Shares. The Reporting Persons acquired the Shares for investment purposes. Notwithstanding any of the foregoing, the Reporting Persons may at any time modify, change, abandon, or replace, some or all of the foregoing purposes and plans and discussions relating thereto or discontinue or re-continue such modifications, changes, abandonments, or replacements at any time. As of November 6, 2025 there were 11,337,720 Shares outstanding, as reported by the Issuer on its Quarterly Report on Form 10-Q filed with the SEC on November 7, 2025. Based on the Shares outstanding as of November 6, 2025: Mark C. Winmill may be deemed to be the beneficial owner of 947,735.2890 Shares which constitute approximately 8.4% of the outstanding Shares, as follows: (i) 339,238.2890 Shares in which he possesses sole voting power and dispositive power and (ii) 608,497 Shares in which he shares voting power and dispositive power with one or more Reporting Persons. Mr. Mark Winmill disclaims beneficial ownership of the Shares owned, or which may be deemed to be owned, by TUXS, the Trust, Winco, MSG, and the Michael M. George Trust. Thomas B. Winmill may be deemed to be the beneficial owner of 587,600 Shares which constitute approximately 5.2% of the outstanding Shares, as follows: (i) 1,100 Shares in which he possesses sole voting power and dispositive power and (ii) 586,500 Shares in which he shares voting power and dispositive power with one or more Reporting Persons. Mr. Thomas Winmill disclaims beneficial ownership of the Shares owned, or which may be deemed to be owned, by TUXS, the Trust, Winco, and MSG. Winco may be deemed to be the beneficial owner of 586,500 Shares which constitute approximately 5.2% of the outstanding Shares, as follows: (i) 147,641 Shares in which it possesses sole voting power and dispositive power and (ii) 438,859 Shares in which it shares voting power and dispositive power with one or more Reporting Persons. Winco disclaims beneficial ownership of the Shares held by TUXS. The Trust may be deemed to be the beneficial owner of 586,500 Shares which constitute approximately 5.2% of the outstanding Shares, over which such Shares it may be deemed to share voting power and dispositive power with one or more Reporting Persons. The Trust disclaims beneficial ownership of all the Shares. TUXS may be deemed to be the direct beneficial owner of 303,758 Shares which constitute approximately 2.7% of the outstanding Shares. Information required by Instruction C of Schedule 13D with respect to other directors and executive officers of and trustees is attached hereto as Exhibit A, Item 5 and is incorporated herein by reference. Mark C. Winmill, Thomas B. Winmill, TUXS, Winco, MSG, and the Michael M. George Trust have the power to vote and to dispose of their respective directly owned Shares. During the past 60 days, the following transactions were effected in the Shares by the Reporting Persons: Reporting Person: Mark C. Winmill Date: 12/5/2025 Transaction: Buy Number of Shares: 3,600 Price per Share: 5.09 Where and How Transaction Effected: Open Market Purchase Reporting Person: Mark C. Winmill Date: 12/5/2025 Transaction: Buy Number of Shares: 800 Price per Share: $5.05 Where and How Transaction Effected: Open Market Purchase Reporting Person: Mark C. Winmill Date: 12/4/2025 Transaction: Buy Number of Shares: 6,000 Price per Share: $5.14149 Where and How Transaction Effected: Open Market Purchase Reporting Person: Mark C. Winmill Date: 12/3/2025 Transaction: Buy Number of Shares: 6,000 Price per Share: $5.1284 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 12/1/2025 Transaction: Buy Number of Shares: 3,062 Price per Share: $5.1774 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/28/2025 Transaction: Buy Number of Shares 3,342 Price per Share: $5.1552 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/26/2025 Transaction: Buy Number of Shares: 4,873 Price per Share: $5.1662 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/25/2025 Transaction: Buy Number of Shares: 4,547 Price per Share: $5.1829 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/24/2025 Transaction: Buy Number of Shares: 4,064 Price per Share: $5.1437 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/21/2025 Transaction: Buy Number of Shares: 6,226 Price per Share: $5.0872 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/20/2025 Transaction: Buy Number of Shares: 5,870 Price per Share: $5.0838 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/19/2025 Transaction: Buy Number of Shares: 6,226 Price per Share: $5.1349 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/18/2025 Transaction: Buy Number of Shares: 5,618 Price per Share: $5.1578 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/17/2025 Transaction: Buy Number of Shares: 6,226 Price per Share: $5.1246 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/14/2025 Transaction: Buy Number of Shares: 7,035 Price per Share: $5.0943 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/13/2025 Transaction: Buy Number of Shares: 6,694 Price per Share: $5.0262 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/12/2025 Transaction: Buy Number of Shares: 6,055 Price per Share: $5.027 Where and How Transaction Effected: Open Market Purchase Reporting Person: Winmill & Co. Incorporated Date: 11/11/2025 Transaction: Buy Number of Shares: 2,069 Price per Share: $4.9698 Where and How Transaction Effected: Open Market Purchase Mark C. Winmill, Thomas B. Winmill, TUXS, Winco, MSG, and the Michael M. George Trust have the right to receive and the power to direct the receipt of dividends from, or the proceeds from the sale of, their respective directly owned Shares. Not applicable. On November 23, 2016, the Issuer entered into a purchase agreement (the "Purchase Agreement") with TUXS, an Issuer affiliate, to acquire all of the membership interests of each of Tuxis Self Storage I LLC, Tuxis Self Storage II LLC, and Tuxis Real Estate II LLC, each a wholly owned subsidiary of TUXS (collectively, the "TUXS Subsidiaries"), for the aggregate purchase price of $7,800,000, comprised of $5,925,000 payable in cash, $975,000 in Shares, and, contingent upon the satisfaction of certain conditions described in the Purchase Agreement, an additional $900,000 cash payment (the "Acquisition"). On December 30, 2016, the Issuer completed the Acquisition for $5,925,000 in cash and 202,703 unregistered and restricted Shares and entered into a registration rights agreement which permits TUXS to request the registration of such Shares. Certain officers and/or directors of the Issuer are officers, directors, and/or trustees of the Reporting Persons. The information provided under Items 2 and 3 of this Schedule 13D are incorporated herein by reference. Exhibit A: Certain Information Required by Instruction C of Schedule 13D. Exhibit B: Agreement to file Schedule 13D jointly. Mark Campbell Winmill /s/ Mark C. Winmill 12/05/2025 Thomas Bassett Winmill /s/ Thomas B. Winmill 12/05/2025 Winmill Family Trust /s/ Thomas B. Winmill 12/05/2025 /s/ Mark C. Winmill 12/05/2025 Winmill & Co. Incorporated /s/ Donald Klimoski II 12/05/2025 Midas Securities Group, Inc. /s/ Russell Kamerman 12/05/2025 TUXIS CORP /s/ Donald Klimoski II 12/05/2025