One Stop Systems, Inc. reported an insider equity transaction by Michael Knowles involving the company’s common stock on June 5, 2026. The Form 4, signed by Knowles on June 12, disclosed that he forfeited 19,675 shares of OSS common stock at a price of $16.89 per share. The transaction was reported as a tax-withholding disposition tied to restricted stock units, rather than an open-market sale. According to the filing’s explanatory note, Knowles forfeited the 19,675 shares when an aggregate of 50,000 vested and outstanding restricted stock units converted into shares of common stock. The shares were withheld to cover tax obligations, using the market price of OSS common stock at the time of forfeiture. This type of transaction is typically reported with transaction code “F,” indicating shares withheld or surrendered to satisfy tax withholding obligations. The restricted stock units involved were part of an earlier grant that Knowles had reported on a Form 4 filed on June 6, 2023. After the reported transaction, the filing notes that Knowles still held 333,311 unvested restricted stock units, all of which remain subject to vesting conditions. The key significance is that the reported reduction in shares reflects tax settlement mechanics associated with vested equity compensation, not necessarily a discretionary sale by the insider. The filing shows continued substantial unvested equity exposure by Knowles to One Stop Systems through his remaining RSUs.