Wenbin Jiang, President and CEO of Cytek Biosciences, Inc. (NASDAQ:CTKB), filed a Form 4 on August 20, 2026, disclosing the vesting of restricted stock units and related tax-withholding share disposals on August 18, 2026.

Key Highlights

  • Four RSU tranches vested: Jiang acquired 11,781, 22,100, 29,002, and 57,212 shares of common stock via RSU conversions on August 18, 2026.
  • Tax-withholding disposals: A total of 36,269 shares (2,869 + 5,382 + 7,062 + 20,956) were withheld and surrendered to the issuer to satisfy tax obligations, at $4.67 per share.
  • Resulting direct ownership: Following all transactions, Jiang held 5,561,029 shares of common stock directly.
  • Remaining RSUs: After the vesting events, Jiang retains 27,494; 139,973; 299,694; and 820,054 RSUs outstanding across the four respective awards.
  • Reporting person roles: Jiang is identified as both a Director and an Officer (President and CEO) of Cytek Biosciences, Inc.

RSU Vesting and Share Withholding Details for Cytek Biosciences President and CEO

According to the filing, Wenbin Jiang converted four separate restricted stock unit awards into common stock on August 18, 2026, with transaction code "M" indicating RSU settlement. Each RSU, as the filing explains, "represents a contingent right to receive one share of the Issuer's common stock." The four tranches added 11,781, 22,100, 29,002, and 57,212 shares, respectively, to Jiang's direct holdings.

In connection with each vesting event, the filing reports that shares were withheld by and surrendered to the issuer to cover tax withholding obligations. The withheld amounts were 2,869, 5,382, 7,062, and 20,956 shares, all at a price of $4.67 per share, recorded under transaction code "F." After accounting for all acquisitions and disposals on that date, Jiang's directly held common stock position stood at 5,561,029 shares, according to the filing.

The filing describes four distinct vesting schedules, each spanning four years. The schedules provide for fractional vesting at 2/48, 3/48, 3/48, and 4/48 of total shares at quarterly intervals, with the earliest originating from a May 18, 2023 start date and the most recent from a May 18, 2026 start date. The RSU awards carry a derivative security price of $0, as stated in Table II of the filing. The Form 4 was signed by Gordon Ho as attorney-in-fact on August 20, 2026.

What Was Disclosed

The filing reports the vesting of four RSU awards and simultaneous tax-withholding share surrenders by Cytek Biosciences' President and CEO on August 18, 2026, resulting in a net direct ownership position of 5,561,029 shares of common stock.