Insider · CIK 0001878824
William D. McCombe
Files at CTKB (Cytek Biosciences, Inc.). First filing Jun 3, 2025, latest Jun 3, 2025.
In brief
William D. McCombe files SEC Form 4 as CFO at CTKB (Cytek Biosciences, Inc.). Since Jun 3, 2025, William D. McCombe has reported 1 open-market buy worth $97k and 0 open-market sells worth $0, the latest filed on Jun 3, 2025.
A track record needs three past buys with six months of prices behind them; William D. McCombe has 0, so none is measured yet.
The newest scored trade: bought $97k of CTKB on Jun 2, 2025, filed Jun 3, 2025, scored 42 (moderate).
Where the trades landed
Last year at the company this insider has traded most, with each buy and sell on the bar it happened.
CTKB: Cytek Biosciences, Inc.
Daily candles, adjusted for splits and dividends. Green arrows are insider buys, red are sells, sized by value. Click a marked bar to open the signal.Charts by TradingView Lightweight Charts™
Signals
This insider’s open-market buys and sells, scored.
| Score | Company | Value | Holdings | Price context | Filed |
|---|---|---|---|---|---|
| 42Moderate | CTKBbuy Cytek Biosciences, Inc. | $97k 35,000 shares | +169% | - |
Transactions
Every row this insider has filed, 49 in all, newest first.
| Date | Company | Transaction | Shares | Price | Value | Holdings after | Filed |
|---|---|---|---|---|---|---|---|
| Aug 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +6,320 | - | - | 117,497 | Aug 20, 2026 |
| Aug 18, 2026 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -2,111 | $4.67 | $9,858 | 115,386 | Aug 20, 2026 |
| Aug 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +13,051 | - | - | 128,437 | Aug 20, 2026 |
| Aug 18, 2026 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -4,392 | $4.67 | $21k | 124,045 | Aug 20, 2026 |
| Aug 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +16,049 | - | - | 140,094 | Aug 20, 2026 |
| Aug 18, 2026 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -5,401 | $4.67 | $25k | 134,693 | Aug 20, 2026 |
| Aug 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -6,320 | $0.00 | $0 | 44,249 | Aug 20, 2026 |
| Aug 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -13,051 | $0.00 | $0 | 134,862 | Aug 20, 2026 |
| Aug 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -16,049 | $0.00 | $0 | 230,042 | Aug 20, 2026 |
| May 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +6,320 | - | - | 101,007 | May 20, 2026 |
| May 18, 2026 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -2,268 | $3.55 | $8,051 | 98,739 | May 20, 2026 |
| May 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +8,700 | - | - | 107,439 | May 20, 2026 |
| May 18, 2026 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -3,122 | $3.55 | $11k | 104,317 | May 20, 2026 |
| May 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +10,699 | - | - | 115,016 | May 20, 2026 |
| May 18, 2026 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -3,839 | $3.55 | $14k | 111,177 | May 20, 2026 |
| May 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -6,320 | $0.00 | $0 | 50,569 | May 20, 2026 |
| May 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -8,700 | $0.00 | $0 | 147,913 | May 20, 2026 |
| May 18, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -10,699 | $0.00 | $0 | 246,091 | May 20, 2026 |
| Mar 10, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +6,320 | - | - | 87,034 | Mar 12, 2026 |
| Mar 10, 2026 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -2,603 | $4.23 | $11k | 84,431 | Mar 12, 2026 |
| Mar 10, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +17,401 | - | - | 101,832 | Mar 12, 2026 |
| Mar 10, 2026 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -7,145 | $4.23 | $30k | 94,687 | Mar 12, 2026 |
| Mar 10, 2026 | CTKB Cytek Biosciences, Inc. | AGrant or award Employee Stock Option (right to buy)derivative | +136,205 | $0.00 | $0 | 136,205 | Mar 12, 2026 |
| Mar 10, 2026 | CTKB Cytek Biosciences, Inc. | AGrant or award Restricted Stock Unitsderivative | +256,790 | $0.00 | $0 | 256,790 | Mar 12, 2026 |
| Mar 10, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -6,320 | $0.00 | $0 | 56,889 | Mar 12, 2026 |
| Mar 10, 2026 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -17,401 | $0.00 | $0 | 156,613 | Mar 12, 2026 |
| Nov 18, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +6,320 | - | - | 73,891 | Nov 20, 2025 |
| Nov 18, 2025 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -2,032 | $5.53 | $11k | 71,859 | Nov 20, 2025 |
| Nov 18, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +13,051 | - | - | 84,910 | Nov 20, 2025 |
| Nov 18, 2025 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -4,196 | $5.53 | $23k | 80,714 | Nov 20, 2025 |
| Nov 18, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -6,320 | $0.00 | $0 | 63,209 | Nov 20, 2025 |
| Nov 18, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -13,051 | $0.00 | $0 | 174,014 | Nov 20, 2025 |
| Aug 18, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +6,320 | - | - | 62,066 | Aug 20, 2025 |
| Aug 18, 2025 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -2,462 | $4.06 | $9,996 | 59,604 | Aug 20, 2025 |
| Aug 18, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +13,051 | - | - | 72,655 | Aug 20, 2025 |
| Aug 18, 2025 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -5,084 | $4.06 | $21k | 67,571 | Aug 20, 2025 |
| Aug 18, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -6,320 | $0.00 | $0 | 69,529 | Aug 20, 2025 |
| Aug 18, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -13,051 | $0.00 | $0 | 187,065 | Aug 20, 2025 |
| Jun 2, 2025 | CTKB Cytek Biosciences, Inc. | POpen-market purchase Common Stock | +35,000 | $2.78 | $97k | 55,746 | Jun 3, 2025 |
| May 19, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +25,283 | - | - | 25,283 | May 21, 2025 |
| May 19, 2025 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -9,848 | $2.69 | $26k | 15,435 | May 21, 2025 |
| May 19, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Common Stock | +8,700 | - | - | 24,135 | May 21, 2025 |
| May 19, 2025 | CTKB Cytek Biosciences, Inc. | FTax withholding Common Stock | -3,389 | $2.69 | $9,116 | 20,746 | May 21, 2025 |
| May 19, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -25,283 | $0.00 | $0 | 75,849 | May 21, 2025 |
| May 19, 2025 | CTKB Cytek Biosciences, Inc. | MOption exercise Restricted Stock Unitsderivative | -8,700 | $0.00 | $0 | 200,116 | May 21, 2025 |
| Mar 4, 2025 | CTKB Cytek Biosciences, Inc. | AGrant or award Employee Stock Option (right to buy)derivative | +330,882 | $0.00 | $0 | 330,882 | Mar 6, 2025 |
| Mar 4, 2025 | CTKB Cytek Biosciences, Inc. | AGrant or award Restricted Stock Unitsderivative | +208,816 | $0.00 | $0 | 208,816 | Mar 6, 2025 |
| May 13, 2024 | CTKB Cytek Biosciences, Inc. | AGrant or award Employee Stock Option (right to buy)derivative | +150,602 | $0.00 | $0 | 150,602 | May 15, 2024 |
| May 13, 2024 | CTKB Cytek Biosciences, Inc. | AGrant or award Restricted Stock Unitsderivative | +101,132 | $0.00 | $0 | 101,132 | May 15, 2024 |
Questions about William D. McCombe
Answered from the filings on this page, as of the latest one.
Is William D. McCombe buying or selling?
Not in the last 12 months. William D. McCombe's latest open-market trade on SEC Form 4 was bought $97k of CTKB on Jun 2, 2025.
How did William D. McCombe's past buys perform?
Not measured yet. InsiderTell needs three past buys with six months of prices to publish a track record, and William D. McCombe has 0.
Where does William D. McCombe file Form 4?
William D. McCombe has filed Form 4 at CTKB (Cytek Biosciences, Inc.) as Chief Financial Officer. A Form 4 is required of officers, directors and holders of more than 10% of a share class within two business days of a trade.
Not investment advice. Scores and forward returns are decision support built from public SEC filings and past prices; they describe what happened after comparable filings, not what will happen after this one. Do your own research and size your risk.