SCHEDULE 13D/A

GLOBAL SELF STORAGE INC

Common Stock, $0.01 par value per share · CUSIP: 37955N106

Event date: 2025-05-21

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Mark Campbell WinmillReported CIK 0001019264

  Shares: 823,877.29 · Class: 7.3%

• Thomas Bassett WinmillReported CIK 0001018500

  Shares: 480,142 · Class: 4.2%

• Winmill Family Trust

  Shares: 479,042 · Class: 4.2%

• Winmill & Co. IncorporatedReported CIK 0000052234

  Shares: 479,042 · Class: 4.2%

• Midas Securities Group, Inc.Reported CIK 0001141394

  Shares: 438,859 · Class: 3.9%

• TUXIS CORPReported CIK 0000736952

  Shares: 303,758 · Class: 2.7%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.