Form 4 for OSS ONE STOP SYSTEMS, INC.

Accepted 2026-05-26 17:44:54 ET · period of report 2026-05-20 · accession 0001193125-26-239727 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X	Filed	Traded	Ticker	Insider	Title	Type	Price	Qty	Owned	ΔOwn	Value
	2026-05-26 17:44	2026-05-20	OSS	Matz Gregory W	Dir	A - Grant	$0.00	+12.0K	86.9K	+16%	$0
	2026-05-26 17:44	2026-05-26	OSS	Matz Gregory W	Dir	S - Sale	$17.52	-8,000	78.9K	-9%	-$140.2K

Purchase Sale Sale after option exercise All abbreviations

#	Table	Security	Date	Code	A/D	Shares	Price	Owned after	Own	Exercise / expiry	Underlying	Footnotes
1	Common	Common Stock	2026-05-20	A	A	11,984	$0.00	86,914	D	—	—	(F1) Represents 11,984 restricted stock units granted to the Reporting Person under the Issuer's 2017 Equity Incentive Plan, as amended (the "Plan"), in connection with the Reporting Person's service as a director of the Issuer, which restricted stock units are subject to vesting conditions. (F2) Includes 11,984 unvested restricted stock units held by the Reporting Person, all of which remain subject to certain vesting conditions and 74,930 shares of common stock.
2	Common	Common Stock	2026-05-26	S	D	8,000	$17.52	78,914	D	—	—	(F3) The Reporting Person sold 8,000 shares of common stock upon conversion of an aggregate 21,000 vested and outstanding restricted stock units into shares of common stock to cover tax withholdings, using the market price of the issuer's common stock at the time of sale. These restricted stock units were part of the grant reported in Table I of the Form 4 filed by the Reporting Person with the Securities and Exchange Commission on May 23, 2025. (F4) Includes 11,984 unvested restricted stock units held by the Reporting Person, all of which remain subject to certain vesting conditions and 66,930 shares of common stock.