INSIDER
01Overview02Follow the Money03Daily Brief04Live05Congress06Directory07Corporate Insiders08Government Money09Political Influence10Institutions11Washington Network12Follow the Power13Disclosure Clock14AI Investigator15Watchlist
ConvergenceINSIDER AlphaSignal ledgerHistorical ReplayRobinhood ChainProofTradingTokenProAccountMethodology
Data sources

Public disclosures only. Scores flag unusual patterns and are not evidence of wrongdoing. Not investment advice.

RH CHAIN…
OverviewFollow the MoneyDaily BriefLiveCongressDirectoryCorporate InsidersGovernment MoneyPolitical InfluenceInstitutionsWashington NetworkFollow the PowerDisclosure ClockAI InvestigatorWatchlistConvergenceINSIDER AlphaSignal ledgerHistorical ReplayRobinhood ChainProofTradingTokenProAccountMethodology
01Overview02Follow the Money03Daily Brief04Live05Congress06Directory07Corporate Insiders08Government Money09Political Influence10Institutions11Washington Network12Follow the Power13Disclosure Clock14AI Investigator15Watchlist
ConvergenceINSIDER AlphaSignal ledgerHistorical ReplayRobinhood ChainProofTradingTokenProAccountMethodology
OverviewFollow the MoneyDaily BriefLiveCongressDirectoryCorporate InsidersGovernment MoneyPolitical InfluenceInstitutionsWashington NetworkFollow the PowerDisclosure ClockAI InvestigatorWatchlistConvergenceINSIDER AlphaSignal ledgerHistorical ReplayRobinhood ChainProofTradingTokenProAccountMethodology
Data sources
SEC FORM 428m ago
HOUSE PTR27m ago
SEC 13F27m ago
ROBINHOOD CHAIN27m ago
SEC FORM 4/Option exerciseVerified data

McCombe William D. reported CTKB

Chief Financial Officer · Cytek Biosciences, Inc. · Common Stock

Side
M
Value
—
Shares
6,320
Price
—
Executed
May 18, 2026
Disclosed
May 20, 2026
Disclosure timeline2 days from execution to publication · legal deadline 2 business days
May 18 executedMay 20, 2026 disclosed

CTKB · daily

Yahoo Finance chart API
▲Execution▼Disclosure●Material company filing●Other disclosed buy●Other disclosed sellUnofficial public endpoint; daily OHLCV, split-adjusted. Replace with a licensed feed for production.

Insider Score

Experimental signal
13/ 100 · ROUTINE
Methodology →
  • Transaction type0 / 20

    Option exercise — administrative, little informational value

  • Relative size+5 / 25

    No reported dollar value · 6.7% of prior position

  • Filing timing0 / 15

    Disclosed 2 business days after execution (deadline: 2)

  • Historical behavior+8 / 15

    First recorded trade by this actor in this security

  • Frequency & clustering0 / 15

    No clustered activity in the dataset

  • Market events0 / 10

    No material company filing within 60 days after the trade

    • The Insider Score measures how far a disclosure deviates from normal filing patterns. A high score is a prompt for research, not evidence of illegal insider trading.

    Other disclosed activity · CTKB

    ScoreActorSecuritySideValueExecutedDisclosedLagSourceEvidence
    9
    YM
    Yan MingDirector, CHIEF TECHNOLOGY OFFICER
    CTKBCytek Biosciences, Inc.
    Tax withholding
    		F$6,286
    1,346 sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    9
    MD
    McCombe William D.Chief Financial Officer
    CTKBCytek Biosciences, Inc.
    Tax withholding
    		F$9,858
    2,111 sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    13
    MD
    McCombe William D.Chief Financial Officer
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    16.0K sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    9
    YM
    Yan MingDirector, CHIEF TECHNOLOGY OFFICER
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    14.2K sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    21
    JW
    Jiang WenbinDirector, PRESIDENT AND CEO
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    11.8K sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    13
    YM
    Yan MingDirector, CHIEF TECHNOLOGY OFFICER
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    6,162 sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    9
    JW
    Jiang WenbinDirector, PRESIDENT AND CEO
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    29.0K sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    9
    JW
    Jiang WenbinDirector, PRESIDENT AND CEO
    CTKBCytek Biosciences, Inc.
    Tax withholding
    		F$25K
    5,382 sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    13
    MD
    McCombe William D.Chief Financial Officer
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    13.1K sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    9
    MD
    McCombe William D.Chief Financial Officer
    CTKBCytek Biosciences, Inc.
    Tax withholding
    		F$25K
    5,401 sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    9
    YM
    Yan MingDirector, CHIEF TECHNOLOGY OFFICER
    CTKBCytek Biosciences, Inc.
    Tax withholding
    		F$7,010
    1,501 sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    12
    JW
    Jiang WenbinDirector, PRESIDENT AND CEO
    CTKBCytek Biosciences, Inc.
    Tax withholding
    		F$98K
    21.0K sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    13
    YM
    Yan MingDirector, CHIEF TECHNOLOGY OFFICER
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    14.2K sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    9
    JW
    Jiang WenbinDirector, PRESIDENT AND CEO
    CTKBCytek Biosciences, Inc.
    Tax withholding
    		F$33K
    7,062 sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    9
    YM
    Yan MingDirector, CHIEF TECHNOLOGY OFFICER
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    7,363 sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    13
    MD
    McCombe William D.Chief Financial Officer
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    6,320 sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    21
    YM
    Yan MingDirector, CHIEF TECHNOLOGY OFFICER
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    7,363 sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    9
    JW
    Jiang WenbinDirector, PRESIDENT AND CEO
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    11.8K sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    13
    JW
    Jiang WenbinDirector, PRESIDENT AND CEO
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    22.1K sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    13
    JW
    Jiang WenbinDirector, PRESIDENT AND CEO
    CTKBCytek Biosciences, Inc.
    Option exercise
    		M—
    57.2K sh
    		Aug 18, 2026Aug 20, 2026
    traded Aug 18, 2026
    		+2dSEC FORM 4

    Evidence

    Evidence

    Verified data

    Read directly from the primary public document; every field below is as reported by the filer.

    Source

    Document
    SEC Form 4
    Publisher
    U.S. Securities and Exchange Commission (EDGAR)
    Document ID
    0001878824-26-000002
    Machine-readable
    Structured copy

    Timestamps

    Event (reported)
    May 18, 2026
    Published
    May 20, 2026
    Ingested by INSIDER
    Nov 5, 03:57 UTC
    Last re-read
    Nov 5, 03:57 UTC

    Extracted facts

    Filer
    McCombe William D.
    Role
    Chief Financial Officer
    Transaction
    Option exerciseAs filed: “M”
    Asset
    Cytek Biosciences, Inc.
    Ticker
    CTKB
    Shares
    6,320
    Execution date (reported)
    May 18, 2026
    Owned after transaction
    101.0K shares
    Days from execution to publication
    2

    What this establishes

    McCombe William D. filed this Form 4 reporting a option exercise of CTKB on May 18, 2026. It became public on May 20, 2026. The filing establishes the reported transaction and the filer's stated role. It does not establish why the trade was made or what the filer knew.

    Extraction

    Method
    Form 4 XML
    Confidence
    1.00
    Chief Financial Officer
    McCombe William D.cik:0001878824
    Issuer
    Cytek Biosciences, Inc.cik:0001831915

    Revision history · 0

    No field has changed since this record was first ingested.

    Company events

    No records

    No material filings recorded for this issuer.