Yan Ming 4
4 · Cytek Biosciences, Inc. · Filed May 20, 2026
Research Summary
AI-generated summary of this filing
Cytek (CTKB) CTO Yan Ming Converts RSUs; 16,647 Net Shares
What Happened
- Yan Ming, Chief Technology Officer and a director of Cytek Biosciences (CTKB), had multiple Restricted Stock Units (RSUs) convert into common stock on May 18, 2026. A total of 22,179 shares were issued on conversion. To satisfy tax-withholding obligations, 5,532 shares were surrendered to the company (share withholding) at an effective withholding value of $3.55 per share, totaling $19,638. The result was a net delivery of 16,647 shares to Yan Ming.
- The Form 4 records the RSU conversions as derivative-to-stock transactions (code M) and the withholding as tax withholding (code F). The $0.00 disposals shown for the derivative entries reflect the conversion of the RSU awards rather than an open-market sale.
Key Details
- Transaction date: May 18, 2026; Form 4 filed May 20, 2026 (appears timely).
- Gross shares converted: 22,179; Shares withheld for taxes: 5,532; Net shares delivered: 16,647.
- Withholding price/value: $3.55 per share; total withholding value ≈ $19,638.
- Transaction codes: M = exercise/conversion of derivative (RSU conversion); F = payment of tax liability via share surrender.
- Footnotes: RSUs represent contingent rights to one share each; vesting schedules noted in filing indicate multi-year staggered vesting (see filing footnotes). Footnote F2 confirms shares were surrendered to satisfy tax withholding.
- Shares owned after transaction: not specified in the provided filing excerpt.
Context
- This was not an open-market sale or purchase but routine RSU vesting with share withholding to cover taxes (a common, administrative transaction). Such withholding transactions typically do not signal a change in insider sentiment the way open-market buys or sales might.
- For retail investors: conversions/vestings increase insider stock holdings on a paper basis (minus withheld shares). The filing shows standard RSU vesting mechanics rather than active trading by the insider.
Insider Transaction Report
Form 4
Yan Ming
DirectorCHIEF TECHNOLOGY OFFICER
Transactions
- Exercise/Conversion
Common Stock
[F1]2026-05-18+4,908→ 4,920,841 total - Tax Payment
Common Stock
[F2]2026-05-18$3.55/sh−1,224$4,345→ 4,919,617 total - Exercise/Conversion
Common Stock
[F1]2026-05-18+3,683→ 4,923,300 total - Tax Payment
Common Stock
[F2]2026-05-18$3.55/sh−919$3,262→ 4,922,381 total - Exercise/Conversion
Common Stock
[F1]2026-05-18+4,108→ 4,926,489 total - Tax Payment
Common Stock
[F2]2026-05-18$3.55/sh−1,025$3,639→ 4,925,464 total - Exercise/Conversion
Common Stock
[F1]2026-05-18+9,480→ 4,934,944 total - Tax Payment
Common Stock
[F2]2026-05-18$3.55/sh−2,364$8,392→ 4,932,580 total - Exercise/Conversion
Restricted Stock Units
[F1][F3]2026-05-18−4,908→ 24,552 total→ Common Stock (4,908 underlying) - Exercise/Conversion
Restricted Stock Units
[F1][F4]2026-05-18−3,683→ 40,520 total→ Common Stock (3,683 underlying) - Exercise/Conversion
Restricted Stock Units
[F1][F5]2026-05-18−4,108→ 69,850 total→ Common Stock (4,108 underlying) - Exercise/Conversion
Restricted Stock Units
[F1][F6]2026-05-18−9,480→ 218,055 total→ Common Stock (9,480 underlying)
Footnotes (6)
- [F1]Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock.
- [F2]Represents the number of shares withheld by and surrendered to the Issuer on May 18, 2026, to satisfy tax withholding obligations that arose in connection with the vesting of the RSU Award.
- [F3]The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2023 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2023 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2023 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2024 and each March 10 thereafter, until fully vested.
- [F4]The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2024 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2024 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2024 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2025 and each March 10 thereafter.
- [F5]The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2025 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2025 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2025 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2026 and each March 10 thereafter, until fully vested.
- [F6]The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2026 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2026 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2026 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2027 and each March 10 thereafter, until fully vested.
Signature
/s/ Valerie Barnett, Attorney-in-Fact|2026-05-20