Form 4 for CTKB Cytek Biosciences, Inc.
Accepted 2026-03-12 00:00:00 ET · period of report 2026-03-10 · accession 0001991396-26-000001 · 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| DM | 2026-03-12 | 2026-03-10 | CTKB | Busque Philippe | SVP, Gbl SALES AND SERVICES | M - OptEx | — | +9,828 | 37.2K | +36% | — |
| DM | 2026-03-12 | 2026-03-10 | CTKB | Busque Philippe | SVP, Gbl SALES AND SERVICES | F - Tax | $4.23 | -3,043 | 35.7K | -8% | -$12.9K |
| DM | 2026-03-12 | 2026-03-10 | CTKB | Busque Philippe | SVP, Gbl SALES AND SERVICES | M - OptEx | $0.00 | -9,828 | 17.7K | -36% | $0 |
| DM | 2026-03-12 | 2026-03-10 | CTKB | Busque Philippe | SVP, Gbl SALES AND SERVICES | A - Grant | $0.00 | +203.9K | 70.7K | New | $0 |
Purchase Sale Sale after option exercise All abbreviations
Every reported transaction
| # | Table | Security | Date | Code | A/D | Shares | Price | Owned after | Own | Exercise / expiry | Underlying | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Common | Common Stock | 2026-03-10 | M | A | 2,049 | — | 30,951 | D | — | — | (F1) Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock. |
| 2 | Common | Common Stock | 2026-03-10 | F | D | 635 | $4.23 | 30,316 | D | — | — | (F2) Represents the number of shares withheld by and surrendered to the Issuer on March 10, 2026, to satisfy tax withholding obligations that arose in connection with the vesting of the RSU Award. |
| 3 | Common | Common Stock | 2026-03-10 | M | A | 2,946 | — | 33,262 | D | — | — | (F1) Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock. |
| 4 | Common | Common Stock | 2026-03-10 | F | D | 912 | $4.23 | 32,350 | D | — | — | (F2) Represents the number of shares withheld by and surrendered to the Issuer on March 10, 2026, to satisfy tax withholding obligations that arose in connection with the vesting of the RSU Award. |
| 5 | Common | Common Stock | 2026-03-10 | F | D | 1,496 | $4.23 | 35,687 | D | — | — | (F2) Represents the number of shares withheld by and surrendered to the Issuer on March 10, 2026, to satisfy tax withholding obligations that arose in connection with the vesting of the RSU Award. |
| 6 | Common | Common Stock | 2026-03-10 | M | A | 4,833 | — | 37,183 | D | — | — | (F1) Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock. |
| 7 | Derivative | Restricted Stock Units | 2026-03-10 | M | D | 4,833 | $0.00 | 43,505 | D | — · — to — | 4,833 Common Stock | (F1) Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock. (F7) 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. |
| 8 | Derivative | Restricted Stock Units | 2026-03-10 | M | D | 2,049 | $0.00 | 6,665 | D | — · — to — | 2,049 Common Stock | (F1) Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock. (F5) The shares subject to the RSU Award shall vest over four years with 13/48 of the total shares underlying the RSU Award vesting on May 18, 2024; 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; 4/48 of the total shares underlying the RSU Award vesting on March 10, 2025 and each March 10 thereafter; and 2/48 of the total shares underlying the RSU Award vesting on May 18, 2025 and each May 18 thereafter. |
| 9 | Derivative | Restricted Stock Units | 2026-03-10 | A | A | 133,226 | $0.00 | 133,226 | D | — · — to — | 133,226 Common Stock | (F1) Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock. (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, 2026 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting August 18, 2026 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting 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. |
| 10 | Derivative | Employee Stock Option (right to buy) | 2026-03-10 | A | A | 70,665 | $0.00 | 70,665 | D | $4.23 · — to 2036-03-09 | 70,665 Common Stock | (F3) The shares subject to the stock option shall vest over 4 years with 1/48 of the total shares underlying the stock option vesting on April 10, 2026 and each month thereafter until fully vested. |
| 11 | Derivative | Restricted Stock Units | 2026-03-10 | M | D | 2,946 | $0.00 | 17,682 | D | — · — to — | 2,946 Common Stock | (F1) Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock. (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, 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. |