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 * RAUN DAVID	2. Issuer Name and Ticker or Trading Symbol ONE STOP SYSTEMS, INC. [ OSS ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director                    _____ 10% Owner __X__ Officer (give title below)    _____ Other (specify below) President and CEO
(Last)          (First)          (Middle) 2235 ENTERPRISE STREET #110	3. Date of Earliest Transaction (MM/DD/YYYY) 7/9/2021
(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	7/9/2021		M		137375	A	(1)	220919	D
Common Stock	7/9/2021		F(2)		66960	D	$6.06	153959	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 Units	(1)	7/9/2021		M			137375	(3)	(3)	Common Stock	137375	$0.00	274750	D

Explanation of Responses:
(1)	Restricted stock units convert into shares of common stock on a one-for-one basis.
(2)	The Reporting Person received 137,375 shares of common stock upon vesting of the restricted stock units, as reported in this Form 4. The Reporting Person forfeited 66,960 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)	The restricted stock units ("RSUs") shall vest over three years, with 1/3 of the RSUs vesting following the one-year anniversary of the date of grant, and the remaining RSUs shall vest in four equal installments, commencing six months after the one-year anniversary of the date of grant and every six months thereafter until fully vested, provided that grantee is still employed on each such vesting date.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
RAUN DAVID 2235 ENTERPRISE STREET #110 ESCONDIDO, CA 92029	X		President and CEO

Signatures
/s/ David Raun		7/12/2021
**Signature of Reporting Person		Date