Nasdaq · CIK 0001831915
CTKB Cytek Biosciences, Inc.
Insider trading from SEC Form 4. Last filing Aug 20, 2026. Close $5.43 on Oct 9, 2026, +62% from the 52-week low and -11% from the high.
In brief
Cytek Biosciences, Inc. (CTKB) has 81 SEC Form 4 filings on file from 10 insiders, the latest filed on Aug 20, 2026. No insider bought or sold on the open market in the last 90 days; rows filed in that time are grants, exercises, tax withholding and other transactions that carry no view on the price.
1 open-market trade has been scored at CTKB. The newest: William D. McCombe (Chief Financial Officer) bought $97k of stock on Jun 2, 2025, filed Jun 3, 2025, scored 42 (moderate).
1 Form 144 notice of planned sales is on file, the latest filed Sep 2, 2026.
Last 90 days
Price and insider trades, last year
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
Open-market buys and sells at Cytek Biosciences, Inc., scored.
| Score | Insider | Value | Holdings | Price context | Filed |
|---|---|---|---|---|---|
| 42Moderate | William D. McCombe Chief Financial Officer buy | $97k 35,000 shares | +169% | - |
Planned sales
Form 144 notices filed before a sale of restricted or control stock, newest first. The sale itself usually reaches a Form 4 within days. All planned sales
| Filed | Seller | Shares | Value | Sale date | Past 3 months |
|---|---|---|---|---|---|
| Sep 2, 2026 | PHILIPPE BUSQUE Officer | 31,666 0.02% of outstanding | $147k | Sep 2, 2026 | none |
Transactions
The newest 50 of 458 rows filed, every code.
| Date | Insider | Transaction | Shares | Price | Value | Holdings after | Filed |
|---|---|---|---|---|---|---|---|
| Aug 18, 2026 | Michael Holder director | MOption exercise Common Stock | +2,181 | - | - | 62,875 | Aug 20, 2026 |
| Aug 18, 2026 | Richard Chin director | MOption exercise Common Stock | +6,107 | - | - | 28,499 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | MOption exercise Common Stock | +11,781 | - | - | 5,488,984 | Aug 20, 2026 |
| Aug 18, 2026 | William D. McCombe Chief Financial Officer | MOption exercise Common Stock | +6,320 | - | - | 117,497 | Aug 20, 2026 |
| Aug 18, 2026 | Glenn P Muir director | MOption exercise Common Stock | +3,086 | - | - | 3,086 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | MOption exercise Common Stock | +7,363 | - | - | 4,804,051 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | FTax withholding Common Stock | -2,869 | $4.67 | $13k | 5,486,115 | Aug 20, 2026 |
| Aug 18, 2026 | Richard Chin director | MOption exercise Restricted Stock Unitsderivative | -6,107 | $0.00 | $0 | 44,790 | Aug 20, 2026 |
| Aug 18, 2026 | William D. McCombe Chief Financial Officer | FTax withholding Common Stock | -2,111 | $4.67 | $9,858 | 115,386 | Aug 20, 2026 |
| Aug 18, 2026 | Michael Holder director | MOption exercise Restricted Stock Unitsderivative | -2,181 | $0.00 | $0 | 7,276 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | FTax withholding Common Stock | -1,778 | $4.67 | $8,303 | 4,802,273 | Aug 20, 2026 |
| Aug 18, 2026 | Glenn P Muir director | MOption exercise Restricted Stock Unitsderivative | -3,086 | $0.00 | $0 | 52,469 | Aug 20, 2026 |
| Aug 18, 2026 | William D. McCombe Chief Financial Officer | MOption exercise Common Stock | +13,051 | - | - | 128,437 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | MOption exercise Common Stock | +22,100 | - | - | 5,508,215 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | MOption exercise Common Stock | +5,525 | - | - | 4,807,798 | Aug 20, 2026 |
| Aug 18, 2026 | William D. McCombe Chief Financial Officer | FTax withholding Common Stock | -4,392 | $4.67 | $21k | 124,045 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | FTax withholding Common Stock | -1,346 | $4.67 | $6,286 | 4,806,452 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | FTax withholding Common Stock | -5,382 | $4.67 | $25k | 5,502,833 | Aug 20, 2026 |
| Aug 18, 2026 | William D. McCombe Chief Financial Officer | MOption exercise Common Stock | +16,049 | - | - | 140,094 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | MOption exercise Common Stock | +6,162 | - | - | 4,812,614 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | MOption exercise Common Stock | +29,002 | - | - | 5,531,835 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | FTax withholding Common Stock | -7,062 | $4.67 | $33k | 5,524,773 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | FTax withholding Common Stock | -1,501 | $4.67 | $7,010 | 4,811,113 | Aug 20, 2026 |
| Aug 18, 2026 | William D. McCombe Chief Financial Officer | FTax withholding Common Stock | -5,401 | $4.67 | $25k | 134,693 | Aug 20, 2026 |
| Aug 18, 2026 | William D. McCombe Chief Financial Officer | MOption exercise Restricted Stock Unitsderivative | -6,320 | $0.00 | $0 | 44,249 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | MOption exercise Common Stock | +14,220 | - | - | 4,825,333 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | MOption exercise Common Stock | +57,212 | - | - | 5,581,985 | Aug 20, 2026 |
| Aug 18, 2026 | William D. McCombe Chief Financial Officer | MOption exercise Restricted Stock Unitsderivative | -13,051 | $0.00 | $0 | 134,862 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | FTax withholding Common Stock | -3,463 | $4.67 | $16k | 4,821,870 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | FTax withholding Common Stock | -20,956 | $4.67 | $98k | 5,561,029 | Aug 20, 2026 |
| Aug 18, 2026 | William D. McCombe Chief Financial Officer | MOption exercise Restricted Stock Unitsderivative | -16,049 | $0.00 | $0 | 230,042 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | MOption exercise Restricted Stock Unitsderivative | -7,363 | $0.00 | $0 | 17,189 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | MOption exercise Restricted Stock Unitsderivative | -11,781 | $0.00 | $0 | 27,494 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | MOption exercise Restricted Stock Unitsderivative | -22,100 | $0.00 | $0 | 139,973 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | MOption exercise Restricted Stock Unitsderivative | -5,525 | $0.00 | $0 | 34,995 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | MOption exercise Restricted Stock Unitsderivative | -29,002 | $0.00 | $0 | 299,694 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | MOption exercise Restricted Stock Unitsderivative | -6,162 | $0.00 | $0 | 63,688 | Aug 20, 2026 |
| Aug 18, 2026 | Wenbin Jiang PRESIDENT AND CEO | MOption exercise Restricted Stock Unitsderivative | -57,212 | $0.00 | $0 | 820,054 | Aug 20, 2026 |
| Aug 18, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | MOption exercise Restricted Stock Unitsderivative | -14,220 | $0.00 | $0 | 203,835 | Aug 20, 2026 |
| Aug 10, 2026 | Ilan Feuchtwang Chief Legal Officer, Secretary | AGrant or award Restricted Stock Unitsderivative | +241,416 | $0.00 | $0 | 241,416 | Aug 12, 2026 |
| Aug 10, 2026 | Ilan Feuchtwang Chief Legal Officer, Secretary | AGrant or award Employee Stock Option (right to buy)derivative | +127,118 | $0.00 | $0 | 127,118 | Aug 12, 2026 |
| Jun 12, 2026 | Ming Yan CHIEF TECHNOLOGY OFFICER | GGift Common Stock | -135,892 | $0.00 | $0 | 4,796,688 | Jun 16, 2026 |
| Jun 10, 2026 | Jack Ball director | MOption exercise Common Stock | +43,973 | - | - | 86,678 | Jun 12, 2026 |
| Jun 10, 2026 | Richard Chin director | AGrant or award Restricted Stock Unitsderivative | +33,333 | $0.00 | $0 | 33,333 | Jun 12, 2026 |
| Jun 10, 2026 | Glenn P Muir director | AGrant or award Restricted Stock Unitsderivative | +55,555 | $0.00 | $0 | 55,555 | Jun 12, 2026 |
| Jun 10, 2026 | Vera Imper director | MOption exercise Common Stock | +43,973 | - | - | 59,679 | Jun 12, 2026 |
| Jun 10, 2026 | Michael Holder director | MOption exercise Common Stock | +43,973 | - | - | 60,694 | Jun 12, 2026 |
| Jun 10, 2026 | Deborah J Neff director | MOption exercise Common Stock | +43,973 | - | - | 59,679 | Jun 12, 2026 |
| Jun 10, 2026 | Jack Ball director | MOption exercise Restricted Stock Unitsderivative | -43,973 | $0.00 | $0 | 0 | Jun 12, 2026 |
| Jun 10, 2026 | Richard Chin director | AGrant or award Director Stock Option (right to buy)derivative | +18,261 | $0.00 | $0 | 18,261 | Jun 12, 2026 |
Insiders
Everyone who has filed a Form 4 here.
- Jack Balldirector
- Richard Chindirector
- Ilan FeuchtwangChief Legal Officer, Secretary
- Michael Holderdirector
- Vera Imperdirector
- Wenbin JiangPRESIDENT AND CEO
- Glenn P Muirdirector
- William D. McCombeChief Financial Officer
- Deborah J Neffdirector
- Ming YanCHIEF TECHNOLOGY OFFICER
Questions about CTKB
Answered from the filings on this page, as of the latest one.
Are insiders buying CTKB?
No. In the last 90 days no insider at Cytek Biosciences, Inc. bought or sold shares on the open market according to SEC Form 4 filings. The rows on file from that period are grants, exercises, tax withholding or other transactions, which carry no view on the price.
Who was the last insider to trade CTKB on the open market?
William D. McCombe (Chief Financial Officer) bought $97k of CTKB on Jun 2, 2025 and filed the Form 4 on Jun 3, 2025. InsiderTell scored 42 (moderate).
How many insiders file Form 4 at Cytek Biosciences, Inc.?
10 people have filed a Form 4 at Cytek Biosciences, Inc., among them Jack Ball (director), Richard Chin (director), Ilan Feuchtwang (Chief Legal Officer, Secretary). Officers, directors and holders of more than 10% of a share class must report their trades within two business days.
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.