InsiderTrades

Form 4 for CTKB Cytek Biosciences, Inc.

Accepted 2026-08-20 16:28:33 ET · period of report 2026-08-18 · accession 0001515140-26-000005 · 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
D 2026-08-20 16:28 2026-08-18 CTKB Holder Michael Dir M - OptEx — +2,181 62.9K +4% —
D 2026-08-20 16:28 2026-08-18 CTKB Holder Michael Dir M - OptEx $0.00 -2,181 7,276 -23% $0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock 2026-08-18 M A 2,181 — 62,875 D — — (F1) Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock.
2 Derivative Restricted Stock Units 2026-08-18 M D 2,181 $0.00 7,276 D — · — to — 2,181 Common Stock (F1) Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock. (F2) The shares underlying the RSU Award shall vest over 3 years, with 2/36 of the total shares underlying the RSU Award vesting on August 18, 2024; 3/36 of the total shares underlying the RSU Award vesting on November 18, 2024 and each November 18 thereafter; 4/36 of the total shares underlying the RSU Award vesting on March 10, 2025 and each March 10 thereafter; 2/36 of the total shares underlying the RSU Award vesting on May 18, 2025 and each May 18 thereafter; and 3/36 of the total shares underlying the RSU Award vesting on August 18, 2025 and each August 18 thereafter. (F2) The shares underlying the RSU Award shall vest over 3 years, with 2/36 of the total shares underlying the RSU Award vesting on August 18, 2024; 3/36 of the total shares underlying the RSU Award vesting on November 18, 2024 and each November 18 thereafter; 4/36 of the total shares underlying the RSU Award vesting on March 10, 2025 and each March 10 thereafter; 2/36 of the total shares underlying the RSU Award vesting on May 18, 2025 and each May 18 thereafter; and 3/36 of the total shares underlying the RSU Award vesting on August 18, 2025 and each August 18 thereafter.