X0508 4 2024-08-13 0001394056 ONE STOP SYSTEMS, INC. OSS 0001664091 Manko Joseph M. Jr. 2235 ENTERPRISE STREET, SUITE 110 ESCONDIDO CA 92029 true false false false false Common Stock 2024-08-13 4 P false 50000 1.94 A 1149899 I Horton Capital Partners Fund, LP Common Stock 2024-08-14 4 P false 25000 1.99 A 1174899 I Horton Capital Partners Fund, LP Common Stock 21000 D The shares are owned directly by Horton Capital Partners Fund, LP ("HCPF"). The Reporting Person, solely by virtue of his position as the managing member of Horton Capital Management, LLC ("HCM"), which serves as the investment manager of HCPF, and as the managing member of Horton Capital Partners, LLC, which serves as the general partner of HCPF, may be deemed to beneficially own the shares held by HCPF for purposes of Section 16. The Reporting Person expressly disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein. Includes 21,000 unvested restricted stock units held by the Reporting Person, all of which remain subject to certain vesting conditions. /s/ Joseph M. Manko Jr. 2024-08-15