OSS One Stop Systems Inc

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).         
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES                                                                                   
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940                       

1. Name and Address of Reporting Person * Reardon James M	2. Issuer Name and Ticker or Trading Symbol ONE STOP SYSTEMS, INC. [ OSS ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                    _____ 10% Owner __X__ Officer (give title below)    _____ Other (specify below) President, CDI
(Last)          (First)          (Middle) 2235 ENTERPRISE ST., STE 110	3. Date of Earliest Transaction (MM/DD/YYYY) 2/22/2021
(Street) ESCONDIDO, CA 92029 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	2/22/2021		M		833	A	(1)	1119532	D
Common Stock	2/22/2021		F(2)		220	D	$6.17	1119312	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Unit	(1)	2/22/2021		M			833	(3)	(3)	Common Stock	833	$0.00	1668	D

Explanation of Responses:
(1)	Restricted stock units convert into common stock on a one-for-one basis.
(2)	The reporting person received 833 shares of common stock upon vesting of the Restricted Stock Units, as reported in this Form 4. The reporting person forfeited 220 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.
(3)	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.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Reardon James M 2235 ENTERPRISE ST. STE 110 ESCONDIDO, CA 92029			President, CDI

Signatures
/s/ James M. Reardon		2/24/2021
**Signature of Reporting Person		Date