SCHEDULE 13D/A 0001193125-23-270319 0001567994 XXXXXXXX LIVE 2 Common Stock, Par Value $0.0001 Per Share 06/04/2025 false 0001394056 68247W109 ONE STOP SYSTEMS, INC.

2235 ENTERPRISE ST STE 110 ESCONDIDO CA 92029

JOSEPH M. MANKO, JR. 215-399-5402 HORTON CAPITAL PARTNERS, LLC 1717 Arch Street, Suite 3740 Philadelphia PA 19103 0001567994 N Horton Capital Partners Fund, LP WC OO N DE 0.00 917343.00 0.00 917343.00 917343.00 N 4.2 PN 0001575443 N Horton Capital Partners, LLC WC OO N DE 0.00 917343.00 0.00 917343.00 917343.00 N 4.2 HC 0001575444 N Horton Capital Management, LLC WC OO N DE 0.00 917343.00 0.00 917343.00 917343.00 N 4.2 IA 0001664091 N Manko Joseph M. Jr. WC OO N X1 21000.00 917343.00 21000.00 917343.00 938343.00 N 4.3 IN Common Stock, Par Value $0.0001 Per Share ONE STOP SYSTEMS, INC. 2235 ENTERPRISE ST STE 110 ESCONDIDO CA 92029 Item 3 is hereby amended and restated to read as follows: The Shares purchased by HCPF were purchased with working capital (which may, at any given time, include margin loans made by brokerage firms in the ordinary course of business) in open market purchases. The aggregate purchase price of the 917,343 Shares beneficially owned by HCPF is approximately $2,040,052, including brokerage commissions. The 21,000 Shares beneficially owned directly by Mr. Manko were awarded to him in his former capacity as a director of the Issuer. Item 5(a) is hereby amended and restated to read as follows: The aggregate percentage of Shares reported owned by each person named herein is based upon 21,589,229 Shares outstanding, as of May 2, 2025, which is the total number of Shares outstanding as reported in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on May 7, 2025. A. HCPF As of the close of business on June 6, 2025, HCPF beneficially owned 917,343 Shares. Percentage: Approximately 4.2% B. HCP As the general partner of HCPF, HCP may be deemed the beneficial owner of the 917,343 Shares owned by HCPF. Percentage: Approximately 4.2% C. HCM As the investment manager of HCPF, HCM may be deemed the beneficial owner of the 917,343 Shares owned by HCPF. Percentage: Approximately 4.2% D. Mr. Manko As of the close of business of June 6, 2025, Mr. Manko directly beneficially owned 21,000 Shares. In addition, as the Managing Member of each of HCP and HCM, Mr. Manko may be deemed the beneficial owner of the 917,343 Shares owned by HCPF. Percentage: Approximately 4.3% Item 5(b) is hereby amended and restated to read as follows: A. HCPF 1. Sole power to vote or direct vote: 0 2. Shared power to vote or direct vote: 917,343 3. Sole power to dispose or direct the disposition: 0 4. Shared power to dispose or direct the disposition: 917,343 B. HCP 1. Sole power to vote or direct vote: 0 2. Shared power to vote or direct vote: 917,343 3. Sole power to dispose or direct the disposition: 0 4. Shared power to dispose or direct the disposition: 917,343 C. HCM 1. Sole power to vote or direct vote: 0 2. Shared power to vote or direct vote: 917,343 3. Sole power to dispose or direct the disposition: 0 4. Shared power to dispose or direct the disposition: 917,343 D. Mr. Manko 1. Sole power to vote or direct vote: 21,000 2. Shared power to vote or direct vote: 917,343 3. Sole power to dispose or direct the disposition: 21,000 4. Shared power to dispose or direct the disposition: 917,343 The filing of this Schedule 13D shall not be deemed an admission that the Reporting Persons are, for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, the beneficial owners of any securities of the Issuer that he or it does not directly own. Each of the Reporting Persons specifically disclaims beneficial ownership of the securities reported herein that he or it does not directly own. Item 5(c) is hereby amended and restated to read as follows: The transactions in securities of the Issuer by the Reporting Persons since the filing of Amendment No. 1 to the Schedule 13D are set forth in Exhibit 1 and are incorporated herein by reference. Item 5(e) is hereby amended and restated to read as follows: As of May 30, 2025, the Reporting Persons ceased to be the beneficial owners of more than 5% of the Shares. 1 - Transactions in Securities. Horton Capital Partners Fund, LP /s/ Joseph M. Manko, Jr. 06/06/2025 Horton Capital Partners, LLC /s/ Joseph M. Manko, Jr. 06/06/2025 Horton Capital Management, LLC /s/ Joseph M. Manko, Jr. 06/06/2025 Manko Joseph M. Jr. /s/ Joseph M. Manko, Jr. 06/06/2025