X0306 4 2022-02-14 0 0001394056 ONE STOP SYSTEMS, INC. OSS 0001729697 Morrison John W Jr. 2235 ENTERPRISE STREET #110 ESCONDIDO CA 92029 0 1 0 0 Chief Financial Officer Common Stock 2022-02-14 4 M 0 2500 A 195953 D Common Stock 2022-02-14 4 F 0 787 4.02 D 195166 D Restricted Stock Unit 2022-02-14 4 M 0 2500 0.00 D Common Stock 2500 0 D Restricted stock units convert into common stock on a one-for-one basis. Includes 110,667 unvested restricted stock units held by the Reporting Person, all of which remain subject to certain vesting conditions. The reporting person received 2,500 shares of common stock upon vesting of the Restricted Stock Units, as reported in this Form 4. The reporting person forfeited 787 shares of common stock underlying the vested and outstanding Restricted Stock Units to cover tax withholdings, using the market price of the issuer's common stock at the time of forfeiture. Prior to the Initial Vesting Date, the Vested Ratio shall be zero. On the Initial Vesting Date, the Vested Ratio shall be 1/6, provided the Grantee's service has not been terminated prior to the Initial Vesting Date. For each six month period of Grantee service from the Initial Vesting Date until the Vested Ratio equals 1/1, the Vested Ratio shall be increased by 1/6. This Restricted Stock Unit will be fully vested after three (3) years of service. The Initial Vesting Date shall be six months following the Date of Restricted Stock Unit Grant. /s/ John Morrison 2022-02-14