Every Form 4 that Cytek Biosciences, Inc. (CTKB) has filed with the SEC in the last 12 months is listed below, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A Form 4 covers the transactions officers, directors and large holders report, so if you follow CTKB and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full CTKB filings page.
Cytek Biosciences, Inc. (CTKB) reported that President and CEO Wenbin Jiang exercised Restricted Stock Units into common stock on August 18, 2026. Four RSU vesting events resulted in the issuance of 120,095 shares of common stock. To cover related tax withholding obligations, 36,269 shares of common stock were withheld and surrendered at $4.67 per share. The RSU awards vest over four-year schedules with specified portions vesting each May 18, August 18, November 18, and March 10.
Cytek Biosciences, Inc. (CTKB) reported that Chief Financial Officer William D. McCombe exercised restricted stock units (RSUs) into 35,420 shares of common stock on August 18, 2026, through three RSU awards. In connection with these vestings, 11,904 shares of common stock were withheld and surrendered to Cytek to satisfy tax withholding obligations at a price of $4.67 per share. Each RSU represents a contingent right to receive one share of common stock, and the related awards vest over four years in specified installment schedules tied to May 18, August 18, November 18 and March 10 of various years.
Cytek Biosciences, Inc. (CTKB) director Glenn P. Muir reported an automatic conversion of 3,086 Restricted Stock Units into 3,086 shares of Common Stock on August 18, 2026. The RSU conversion price was $0.00 per share.
Following this transaction, Muir’s directly held RSU balance tied to this award is reported as 52,469 units, and his directly held Common Stock position from this transaction is 3,086 shares3 years in multiple tranches, including 2/36 of the total shares vesting on August 18, 2026, and additional 3/36 and 4/36 installments on specified dates thereafter, as long as the vesting conditions are met.
Cytek Biosciences, Inc. (CTKB) reported that director Michael Holder exercised restricted stock units into common stock. On August 18, 2026, 2,181 Restricted Stock Units converted into 2,181 shares of common stock, increasing his directly held common shares to 62,875 and reducing his Restricted Stock Units to 7,276. Each RSU represents a contingent right to receive one share of common stock, with the underlying RSU award vesting in scheduled tranches through at least August 18, 2025 as described in the vesting footnote.
Cytek Biosciences, Inc. (CTKB) director Richard Chin reported an exercise and conversion of 6,107 Restricted Stock Units (RSUs) into 6,107 shares of Common Stock on August 18, 2026. Following this transaction, he directly held 28,499 shares of Common Stock and 44,790 RSUs. Each RSU represents a contingent right to receive one share of common stock, with the RSU award vesting in scheduled tranches between August 18, 2025 and August 18, 2026.
Cytek Biosciences, Inc. (CTKB) reported that director and Chief Technology Officer Yan Ming had several Restricted Stock Unit ("RSU Award") tranches vest on August 18, 2026, each RSU converting into one share of common stock. In total, 33,270 shares of common stock were acquired through exercises or conversions of RSUs. To cover related tax obligations, 8,088 shares of common stock were withheld and surrendered to Cytek at $4.67 per share. The RSU Awards vest over four-year schedules, with specified fractions of the total shares vesting on May 18, August 18, November 18, and March 10 of each year for the different grants.
Cytek Biosciences, Inc. granted Chief Legal Officer and Secretary Ilan Feuchtwang new equity awards. The awards consist of 241,416 Restricted Stock Units, each representing one share of common stock, and an option for 127,118 shares of common stock at an exercise price of $4.66 per share, expiring on August 9, 2036. The RSUs and options vest over four years under specified installment schedules, in each case subject to the executive’s Continuous Service under the company’s 2021 Equity Incentive Plan.
Cytek Biosciences, Inc. director and Chief Technology Officer Yan Ming reported a bona fide gift of common stock. On the reported date, Ming transferred 135,892 shares of Cytek Biosciences common stock as a gift at a stated price of $0.00 per share. After this disposition, Ming continued to hold 4,796,688 shares of common stock directly, indicating that the gifted amount represents a relatively small portion of his overall reported holdings. As a gift transaction, this Form 4 reflects a non-market transfer rather than an open-market purchase or sale.
Cytek Biosciences director Jack Ball exercised a vested equity award for 43,973 shares of common stock through conversion of Restricted Stock Units. The RSU award fully vested on June 10, 2026, and after this non‑market, compensation-related transaction he directly holds 86,678 shares of Cytek common stock.
Cytek Biosciences director Glenn P. Muir reported equity awards that increase his potential ownership in the company. He received a stock option for 29,835 shares of common stock at an exercise price of $4.05 per share, expiring on June 10, 2036. He also received 55,555 restricted stock units, each representing one share of common stock.
The option vests in equal monthly installments over three years following the June 10, 2026 grant date. The restricted stock units vest in tranches between August 18, 2026 and August 18, 2027 based on a detailed schedule, tying full ownership to continued service.
Cytek Biosciences, Inc. director Richard Chin reported receiving new equity awards as part of his board compensation. He was granted an option for 18,261 shares of common stock at an exercise price of $4.05 per share, expiring on June 10, 2036. He also received 33,333 restricted stock units, each representing one share of common stock. Both the option and RSU award vest 100% on the earlier of June 10, 2027 or the company’s 2027 annual stockholder meeting, if that meeting is held in June 2027. These are compensation-related grants, not open-market purchases or sales.
Cytek Biosciences director Imper Vera increased her equity stake through compensation-related awards. On June 10, 2026, she exercised 43,973 Restricted Stock Units that had fully vested the same day, receiving an equal number of common shares and bringing her direct common stock holdings to 59,679 shares.
She also received grants of 18,261 director stock options with a $4.05 exercise price expiring on June 10, 2036, and 33,333 new Restricted Stock Units. Both the new option and RSU awards vest 100% on the earlier of June 10, 2027 or Cytek’s 2027 annual meeting of stockholders, if that meeting is held in June 2027. No open-market buys or sales were reported.
Cytek Biosciences director Deborah J. Neff increased her equity stake through compensation-related transactions. On June 10, 2026, she exercised previously granted restricted stock units, receiving 43,973 shares of common stock and bringing her direct holdings to 59,679 shares.
On the same date, she received a director stock option for 18,261 shares of common stock at an exercise price of $4.05 per share, expiring on June 10, 2036. She was also granted 33,333 new restricted stock units, each representing one share of common stock, which are scheduled to vest on the earlier of June 10, 2027 or the company’s 2027 annual meeting of stockholders if held in June 2027.
Cytek Biosciences director Michael Holder reported equity compensation activity. He exercised 43,973 Restricted Stock Units into Common Stock, and following these transactions he holds 60,694 Common Stock shares directly. The filing shows no open‑market buys or sells.
Holder also received a grant of 18,261 director stock options with a $4.05 exercise price, expiring on June 10, 2036. In addition, he was granted 33,333 new RSUs. Both the new option grant and RSUs are scheduled to vest 100% on the earlier of June 10, 2027 or Cytek’s 2027 annual meeting of stockholders, if that meeting is held in June 2027.
Cytek Biosciences director Michael Holder reported a routine equity compensation event. He acquired 1,454 shares of common stock on May 18, 2026 through the exercise or conversion of restricted stock units, with no open-market purchase or sale involved.
After this transaction, he directly holds 16,721 shares of common stock and 9,457 restricted stock units. The RSU award vests in multiple tranches between August 18, 2024 and August 18, 2025, gradually converting into common shares over time.
Cytek Biosciences, Inc. director Richard Chin reported a routine equity compensation event. On May 18, 2026, he exercised 6,107 Restricted Stock Units, receiving the same number of shares of common stock at a stated price of $0.00 per share.
Following the transaction, Chin directly holds 22,392 shares of Cytek common stock and 50,897 Restricted Stock Units. The RSU Award represents the right to receive one share of common stock per unit and is scheduled to vest in multiple tranches between August 18, 2025 and August 18, 2026.
Cytek Biosciences, Inc. director and Chief Technology Officer Yan Ming reported routine equity compensation activity. On May 18, 2026, Ming exercised restricted stock units that converted into 22,179 shares of common stock in total. To cover tax obligations tied to these vestings, 5,532 shares of common stock were withheld and surrendered to the company at $3.55 per share, rather than sold on the open market. After these transactions, Ming directly owned 4,919,617 shares of Cytek common stock.
Cytek Biosciences SVP Philippe Busque reported compensation-related stock activity. On May 18, 2026, he exercised awards covering 10,464 shares of common stock, converting vested restricted stock units into shares. To cover tax withholding obligations, 2,685 shares were surrendered back to the company at $3.55 per share rather than sold on the open market.
Following these transactions, Busque directly holds 36,448 shares of Cytek Biosciences common stock and 5,641 unvested restricted stock units that may convert into shares as they vest over time under multi-year vesting schedules.
Cytek Biosciences, Inc. President and CEO Wenbin Jiang reported routine equity compensation activity involving restricted stock units that vested into common stock. On May 18, 2026, he exercised RSU awards to acquire 80,062 shares of common stock and had 25,542 shares withheld to cover tax obligations at $3.55 per share.
Following these transactions, Jiang directly held about 5.43 million shares of Cytek common stock and continued to hold 39,275 restricted stock units that will vest over time under multi-year schedules described in the RSU footnotes. No open-market purchases or sales were reported.
Cytek Biosciences Chief Financial Officer William D. McCombe reported routine equity compensation activity tied to Restricted Stock Units on May 18, 2026. He exercised RSU awards into 25,719 shares of common stock and had 9,229 shares withheld at $3.55 per share to cover tax obligations. Following these transactions, he directly holds 98,739 shares of common stock. The footnotes explain that each RSU represents a contingent right to one share and outline multi-year vesting schedules, indicating these events stem from scheduled vesting rather than open-market trades.
Cytek Biosciences, Inc.’s chief legal officer Valerie Barnett reported routine equity compensation activity. On May 18, 2026, she exercised 24,295 Restricted Stock Units into common shares and had 8,719 shares withheld at $3.55 per share to cover tax obligations.
These tax-withholding dispositions were not open-market sales. After the transactions, she directly held 136,009 shares of common stock and continued to hold 12,280 Restricted Stock Units, reflecting ongoing equity-based compensation rather than discretionary trading.
Cytek Biosciences, Inc. director and chief technology officer Yan Ming reported a bona fide gift of 1,176,000 shares of Common Stock. The transfer carried a reported price of $0.00 per share, reflecting that it was a non-cash gift, not a market sale. After this disposition, Ming’s direct holdings are reported at 4,915,933 Common Stock shares, indicating he retains a substantial ownership position in the company.
Cytek Biosciences director Richard Chin exercised restricted stock units into common shares. On this date, 6,107 Restricted Stock Units converted into 6,107 shares of common stock at no exercise price. After the transaction, he directly holds 16,285 shares of common stock and 57,004 Restricted Stock Units.
The footnotes explain that each RSU represents a contingent right to one share of common stock and describe a multi‑date vesting schedule, with portions of the award vesting on specified dates in August, November, March, and May until fully vested.
Cytek Biosciences, Inc. Chief Legal Officer Valerie Barnett reported equity compensation and vesting activity. She received a stock option grant for 120,114 shares of common stock at an exercise price of $4.23 per share, vesting monthly over four years. She was also granted 226,453 restricted stock units (RSUs) that vest over four years on specified May, August, November, and March dates. On the same date, several earlier RSU awards vested, converting a total of 29,722 RSUs into common shares. Of these, 11,748 shares were withheld at $4.23 per share to cover tax obligations, and the remainder increased her directly held common stock to 134,436 shares. These are compensation-related grants, exercises, and tax withholdings rather than open‑market purchases or sales.
Cytek Biosciences SVP Philippe Busque reported equity compensation and vesting activity. On March 10, 2026 he received an employee stock option for 70,665 shares of common stock at an exercise price of $4.23 per share, vesting monthly over four years. He was also granted 133,226 restricted stock units, each representing one share of common stock, scheduled to vest over four years under specified annual dates.
On the same date, several existing RSU awards vested, leading to the issuance of 9,828 shares of common stock through derivative exercises, while 3,043 shares were withheld by the company at $4.23 per share to cover tax obligations. Following these transactions, Busque directly held 35,687 shares of common stock.
Cytek Biosciences President and CEO Wenbin Jiang reported several equity compensation transactions. He was granted an employee stock option for 485,545 shares of common stock at an exercise price of $4.23 per share, vesting monthly over four years, and a new award of 915,407 restricted stock units (RSUs) that also vest over four years on specified May, August, November, and March dates.
On the same date, previously granted RSUs vested and were converted into common stock in tranches of 15,708, 29,467, and 38,669 shares. To satisfy tax withholding obligations from these vestings, 3,825, 7,747, and 9,416 shares of common stock were surrendered back to the company at $4.23 per share. After these transactions, Jiang directly owned 5,422,683 shares of common stock.
Cytek Biosciences Chief Financial Officer William D. McCombe reported new equity awards and routine vesting-related activity. He received an employee stock option for 136,205 shares of common stock at an exercise price of $4.23 per share, expiring on March 9, 2036, which vests monthly over four years. He was also granted 256,790 restricted stock units, scheduled to vest over four years under detailed annual vesting schedules. On the same date, 6,320 and 17,401 RSUs converted into common shares, and a total of 9,748 common shares were surrendered at $4.23 per share to cover tax withholding obligations. Following these transactions, he directly holds 94,687 shares of common stock.
Cytek Biosciences, Inc. director and Chief Technology Officer Yan Ming reported several equity compensation transactions. On March 10, 2026, Ming received an employee stock option for 120,688 shares of common stock at an exercise price of $4.23 per share, vesting monthly over four years. He also received 227,535 Restricted Stock Units (RSUs), which vest over four years in specified tranches each May 18, August 18, November 18, and March 10 according to the award schedules.
Ming exercised previously granted RSUs covering a total of 25,400 shares of common stock. Of the resulting shares, 7,731 shares were withheld and surrendered to Cytek Biosciences at $4.23 per share to satisfy tax withholding obligations, and the remaining shares increased his direct common stock holdings. After these transactions, Ming directly owned 6,091,933 shares of common stock.
Cytek Biosciences director Michael Holder reported the vesting and exercise of restricted stock units into common shares as part of his equity compensation. On March 10, 2026, 2,908 RSUs converted into 2,908 shares of common stock at no cash cost, lifting his directly held common stock to 15,267 shares after the transaction.
Cytek Biosciences president and CEO Wenbin Jiang reported equity award activity involving restricted stock units and common shares. On February 18, 2026, 4,514 restricted stock units were converted into 4,514 shares of common stock at a price of 0.00 per share.
The Form 4 shows that 1,339 of these common shares, valued at 4.20 per share, were withheld and surrendered to Cytek Biosciences to cover tax withholding obligations tied to the vesting of this RSU award. After these transactions, Jiang directly held 5,359,827 shares of common stock.
Cytek Biosciences, Inc. director and Chief Technology Officer Yan Ming reported equity compensation activity involving restricted stock units (RSUs) and common stock. On February 18, 2026, 1,332 RSUs were converted into 1,332 shares of common stock at a stated price of $0.0000 per share.
On the same date, 395 shares of common stock at $4.20 per share were withheld and surrendered to Cytek to cover tax obligations arising from the RSU vesting, described as a tax-withholding disposition rather than an open-market sale. Following these transactions, Yan Ming directly held 6,074,264 common shares.
Cytek Biosciences, Inc. chief legal officer Valerie Barnett reported equity award activity involving restricted stock units and common shares. On February 18, 2026, 1,346 restricted stock units were exercised into 1,346 shares of common stock at a stated price of $0.00 per share.
On the same date, 525 common shares at $4.20 per share were withheld and surrendered to Cytek Biosciences to cover tax withholding obligations related to the vesting of this RSU award. After these transactions, Barnett directly held 116,462 shares of Cytek Biosciences common stock. The RSU award vests quarterly over four years, with an initial 4/48th tranche vesting on May 18, 2022, and 3/48th of the total shares vesting on each subsequent August 18, November 18, February 18, and May 18.
Cytek Biosciences (CTKB) chief technology officer and director reported multiple equity transactions on November 18, 2025 related to previously granted restricted stock units (RSUs). Several RSU tranches were converted into common stock, including blocks of 1,981, 7,363, 5,525 and 6,162 shares, reflecting ongoing vesting of long-term equity awards. To cover tax withholding from these vestings, a total of 4,? (aggregate of 483, 1,793, 1,346 and 1,501) shares were withheld and surrendered to the company at a price of $5.53 per share, rather than being sold on the open market. After these transactions, the insider directly beneficially owned 6,073,327 shares of Cytek common stock. The RSU grants continue to vest over multiple years on specified quarterly and annual dates.
Cytek Biosciences (CTKB) senior executive reports RSU vesting and share withholding transactions. On November 18, 2025, the SVP, Global Sales and Services converted multiple batches of restricted stock units (RSUs) into common stock and had shares withheld to cover taxes.
Form 4 data shows RSU exercises adding 1,536, 2,210, and 3,625 shares of common stock, with tax withholding sales of 393, 565, and 927 shares at $5.53 per share. After these transactions, the executive directly owned 28,902 shares of Cytek common stock.
The filing also reports remaining unvested or unsettled RSUs, with derivative holdings of 8,714, 20,628, and 48,338 RSUs, each tied to multi-year vesting schedules that allocate specific fractions of each award to vest on set dates in May, August, November, and March until fully vested.
Cytek Biosciences, Inc. insider activity: the company’s Chief Legal Officer reported multiple transactions on common stock tied to vesting of restricted stock units (RSUs) on November 18, 2025. Several RSU awards were converted into common shares, each RSU representing a right to receive one share of Cytek common stock.
On the same date, shares were also withheld and surrendered to Cytek to cover tax withholding obligations at a price of $5.53 per share. After these RSU conversions and tax withholdings, the reporting person directly beneficially owned 115,641 shares of Cytek common stock. The RSU awards vest over four-year schedules with quarterly and annual vesting dates as described in the filing.
Cytek Biosciences, Inc. (CTKB) reported insider equity activity by its Chief Financial Officer on 11/18/2025. The filing shows the vesting and settlement of restricted stock units (RSUs) into common stock, along with shares withheld to cover taxes. The CFO acquired 6,320 shares of common stock upon RSU vesting, then had 2,032 shares withheld and surrendered to the company at $5.53 per share for tax obligations. A second RSU vesting added 13,051 shares, followed by 4,196 shares withheld at the same price for taxes. After these transactions, the CFO directly owned 80,714 shares of common stock and continued to hold additional unvested RSUs, reflecting ongoing equity-based compensation rather than an open-market sale.
Cytek Biosciences (CTKB) president and CEO, who also serves as a director, reported several equity transactions on November 18, 2025 related to restricted stock units (RSUs). Multiple RSU awards were converted into common stock, with 6,758, 11,781, 22,100 and 29,002 shares of common stock issued as each RSU grant vested.
To cover tax withholding from these vestings, the issuer withheld and received back 2,660, 4,636, 8,697 and 11,413 shares at a price of $5.53 per share. After the reported transactions, the executive beneficially owned 5,356,652 shares of Cytek common stock directly, and continued to hold RSU awards covering 4,514, 62,837, 206,273 and 386,699 units that will vest over multiple years on specified quarterly and annual dates.
Cytek Biosciences (CTKB) filed a Form 4 showing a director’s equity activity. On 11/18/2025, the reporting person acquired 2,181 shares of common stock through the vesting and settlement of restricted stock units, reported with transaction code "M." After this transaction, the person directly owned 12,359 shares of common stock.
The filing also shows activity in derivative securities. On the same date, 2,181 restricted stock units were converted into common stock at an exercise price of $0, leaving 13,819 restricted stock units beneficially owned directly. Each restricted stock unit represents a contingent right to receive one share of Cytek Biosciences common stock, subject to a multi-date vesting schedule.
Cytek Biosciences (CTKB) reported an insider equity transaction by a company director on 11/18/2025. The filing shows that 6,107 shares of common stock were acquired through the vesting and settlement of restricted stock units (RSUs), coded as transaction type “M,” which reflects the conversion of a derivative security into common stock.
After this transaction, the director beneficially owns 10,178 shares of Cytek common stock directly and continues to hold 63,111 RSUs. Each RSU represents the right to receive one share of common stock. The RSU award vests over time in tranches on specific dates, including portions vesting on August 18, November 18, March 10, May 18 and August 18 of future years until the award is fully vested.