Comparable stake leader
BlackRock, Inc.
SEC ownership of Cytek Biosciences, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001831915.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
30 Jun 2026
- Public ticker
- CTKB on Nasdaq
- Parsed ownership sources
-
13F, 13D/G, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
BlackRock, Inc.
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
BlackRock, Inc.
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
30 Jun 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001831915
- Issuer location
- Fremont, CA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Cytek Biosciences, Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
BlackRock, Inc.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
30 Jun 2026
13F
13D/G
3/4/5
Lead comparable stake: 7.2%
13D/G row: BlackRock, Inc.
Showing 1-8 of 50 holder rows.
Quick read
BlackRock, Inc. leads the comparable SEC ownership view at 7.2%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens BlackRock, Inc.'s linked filing trail.
Comparable ownership
Top 5
BlackRock, Inc.
7.2%
MILLENNIUM MANAGEMENT LLC
7.2%
Boston Partners
5.9%
Topline Capital Management, LLC
5.3%
BROWN CAPITAL MANAGEMENT LLC
3.9%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| BlackRock, Inc. |
13F
13D/G
Company
|
7.2%
from 13D/G
|
$42,433,388
9,578,643 shares
|
— | 30 Jun 2026 |
| MILLENNIUM MANAGEMENT LLC |
13D/G
13F
Company
|
7.2%
|
$41,367,384
9,338,010 shares
|
+$6,490,437 | 30 Jun 2026 |
| Boston Partners |
13F
13D/G
Company
|
5.9%
from 13D/G
|
$33,942,877
7,660,943 shares
|
— | 30 Jun 2026 |
| Topline Capital Management, LLC |
13D/G
13F
Company
|
5.3%
|
$28,140,515
6,780,847 shares
|
$0 | 25 Sep 2025 |
| BROWN CAPITAL MANAGEMENT LLC |
13D/G
|
3.9%
|
$17,204,316
4,958,016 shares
|
-$8,695,650 | 30 Sep 2025 |
| Don M. Hardison |
3/4/5
Director
|
0.01%
|
$152,819
15,706 shares
mixed-class rows
|
— | 05 Jun 2025 |
| HHLR ADVISORS, LTD. |
13F
Company
|
5.1%
|
$29,490,643
6,657,030 shares
|
— | 30 Jun 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
Company
|
3.8%
|
$21,882,415
4,939,597 shares
|
— | 30 Jun 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Insider buy and sell flow is broadly balanced over the last 12 months. No Buy or Sell transactions have been reported since 28 Aug 2025.
Buys
$0
Insiders: 0
Sells
$0
Insiders: 0
Net
$0
Shares: 0
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 0
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 0 | $0 | $0 | $0 |
| 3-6 | 0 | 0 | $0 | $0 | $0 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 21 reporting-owner rows connected to Cytek Biosciences, Inc.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
21
Largest Forms 3/4/5 holder
RA CAPITAL MANAGEMENT, L.P.
Net 12M change
$0
Latest report
18 Aug 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. | Director, 10%+ Owner | $127,120,013 | Mixed | 14 Mar 2022 | ||
| Wenbin Jiang | PRESIDENT AND CEO, Director | $25,791,656 | Mixed | 18 Aug 2026 | ||
| Ming Yan | CHIEF TECHNOLOGY OFFICER, Director | $21,712,948 | Mixed | 18 Aug 2026 | ||
| Feng Deng | Director | $4,216,100 | Mixed | 22 Jul 2021 | ||
| William D. McCombe | Chief Financial Officer | $1,705,502 | Mixed | 18 Aug 2026 | ||
| Valerie Barnett | Chief Legal Officer | $1,060,260 | Mixed | 18 May 2026 | ||
| Patrik Jeanmonod | Chief Financial Officer | $1,022,691 | Mixed | 11 Mar 2024 | ||
| Paul Christopher Williams | Chief Operating Officer | $791,797 | Mixed | 19 Aug 2024 | ||
| Allen Poirson | Svp Bus. And Corp. Dev. | $512,724 | Mixed | 18 Nov 2024 | ||
| Jack Ball | Director | $472,390 | Mixed | 10 Jun 2026 | ||
| Michael Holder | Director | $382,798 | Mixed | 18 Aug 2026 | ||
| Vera Imper | Director | $354,405 | Mixed | 10 Jun 2026 | ||
| Deborah J. Neff | Director | $354,405 | Mixed | 10 Jun 2026 | ||
| Jonathan Todd Garland | Chief Commercial Officer | $319,931 | Mixed | 18 Aug 2023 | ||
| Philippe Busque | Svp, Global Sales And Services | $305,578 | Mixed | 18 May 2026 | ||
| Don M. Hardison | Director | $152,819 | Mixed | 05 Jun 2025 | ||
| Richard Chin | Director | $126,250 | Median | 18 Aug 2026 | ||
| Glenn P. Muir | Director | $13,670 | Median | 18 Aug 2026 | ||
| Ilan Feuchtwang | Chief Legal Officer, Secretary | Mixed | 10 Aug 2026 | |||
| Gisele Dion | Director | Mixed | 14 Jun 2023 |
Recent insider transactions for Cytek Biosciences, Inc.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Wenbin Jiang | CTKB | Common Stock | Tax liability | -0.66% | -36,269 | 5,486,115 | 18 Aug 2026 | Direct | ||
| Wenbin Jiang | CTKB | Common Stock | Options Exercise | 2.2% | 120,095 | 5,581,985 | 18 Aug 2026 | Direct | ||
| Wenbin Jiang | CTKB | Restricted Stock Units | Options Exercise | -81.4% | -120,095 | 27,494 | 18 Aug 2026 | Direct | ||
| William D. McCombe | CTKB | Common Stock | Tax liability | -9.35% | -11,904 | 115,386 | 18 Aug 2026 | Direct | ||
| William D. McCombe | CTKB | Common Stock | Options Exercise | 33.8% | 35,420 | 140,094 | 18 Aug 2026 | Direct | ||
| William D. McCombe | CTKB | Restricted Stock Units | Options Exercise | -44.5% | -35,420 | 44,249 | 18 Aug 2026 | Direct | ||
| Glenn P. Muir | CTKB | Common Stock | Options Exercise | 3,086 | 3,086 | 18 Aug 2026 | Direct | |||
| Glenn P. Muir | CTKB | Restricted Stock Units | Options Exercise | -5.55% | -3,086 | 52,469 | 18 Aug 2026 | Direct | ||
| Michael Holder | CTKB | Common Stock | Options Exercise | 3.59% | 2,181 | 62,875 | 18 Aug 2026 | Direct | ||
| Michael Holder | CTKB | Restricted Stock Units | Options Exercise | -23.1% | -2,181 | 7,276 | 18 Aug 2026 | Direct | ||
| Richard Chin | CTKB | Common Stock | Options Exercise | 27.3% | 6,107 | 28,499 | 18 Aug 2026 | Direct | ||
| Richard Chin | CTKB | Restricted Stock Units | Options Exercise | -12% | -6,107 | 44,790 | 18 Aug 2026 | Direct | ||
| Ming Yan | CTKB | Common Stock | Tax liability | -0.17% | -8,088 | 4,802,273 | 18 Aug 2026 | Direct | ||
| Ming Yan | CTKB | Common Stock | Options Exercise | 0.69% | 33,270 | 4,825,333 | 18 Aug 2026 | Direct | ||
| Ming Yan | CTKB | Restricted Stock Units | Options Exercise | -65.9% | -33,270 | 17,189 | 18 Aug 2026 | Direct | ||
| Ilan Feuchtwang | CTKB | Employee Stock Option (right to buy) | Award | 127,118 | 127,118 | 10 Aug 2026 | Direct | |||
| Ilan Feuchtwang | CTKB | Restricted Stock Units | Award | 241,416 | 241,416 | 10 Aug 2026 | Direct | |||
| Ming Yan | CTKB | Common Stock | Gift | -2.75% | -135,892 | 4,796,688 | 12 Jun 2026 | Direct | ||
| Jack Ball | CTKB | Common Stock | Options Exercise | 103% | 43,973 | 86,678 | 10 Jun 2026 | Direct | ||
| Jack Ball | CTKB | Restricted Stock Units | Options Exercise | -100% | -43,973 | 0 | 10 Jun 2026 | Direct | ||
| Glenn P. Muir | CTKB | Director Stock Option (right to buy) | Award | 29,835 | 29,835 | 10 Jun 2026 | Direct | |||
| Glenn P. Muir | CTKB | Restricted Stock Units | Award | 55,555 | 55,555 | 10 Jun 2026 | Direct | |||
| Richard Chin | CTKB | Director Stock Option (right to buy) | Award | 18,261 | 18,261 | 10 Jun 2026 | Direct | |||
| Richard Chin | CTKB | Restricted Stock Units | Award | 33,333 | 33,333 | 10 Jun 2026 | Direct | |||
| Vera Imper | CTKB | Common Stock | Options Exercise | 280% | 43,973 | 59,679 | 10 Jun 2026 | Direct | ||
| Vera Imper | CTKB | Restricted Stock Units | Options Exercise | -100% | -43,973 | 0 | 10 Jun 2026 | Direct | ||
| Vera Imper | CTKB | Director Stock Option (right to buy) | Award | 18,261 | 18,261 | 10 Jun 2026 | Direct | |||
| Vera Imper | CTKB | Restricted Stock Units | Award | 33,333 | 33,333 | 10 Jun 2026 | Direct | |||
| Deborah J. Neff | CTKB | Common Stock | Options Exercise | 280% | 43,973 | 59,679 | 10 Jun 2026 | Direct | ||
| Deborah J. Neff | CTKB | Restricted Stock Units | Options Exercise | -100% | -43,973 | 0 | 10 Jun 2026 | Direct | ||
| Deborah J. Neff | CTKB | Director Stock Option (right to buy) | Award | 18,261 | 18,261 | 10 Jun 2026 | Direct | |||
| Deborah J. Neff | CTKB | Restricted Stock Units | Award | 33,333 | 33,333 | 10 Jun 2026 | Direct | |||
| Michael Holder | CTKB | Common Stock | Options Exercise | 263% | 43,973 | 60,694 | 10 Jun 2026 | Direct | ||
| Michael Holder | CTKB | Restricted Stock Units | Options Exercise | -100% | -43,973 | 0 | 10 Jun 2026 | Direct | ||
| Michael Holder | CTKB | Director Stock Option (right to buy) | Award | 18,261 | 18,261 | 10 Jun 2026 | Direct | |||
| Michael Holder | CTKB | Restricted Stock Units | Award | 33,333 | 33,333 | 10 Jun 2026 | Direct | |||
| Michael Holder | CTKB | Common Stock | Options Exercise | 9.52% | 1,454 | 16,721 | 18 May 2026 | Direct | ||
| Michael Holder | CTKB | Restricted Stock Units | Options Exercise | -13.3% | -1,454 | 9,457 | 18 May 2026 | Direct | ||
| Richard Chin | CTKB | Common Stock | Options Exercise | 37.5% | 6,107 | 22,392 | 18 May 2026 | Direct | ||
| Richard Chin | CTKB | Restricted Stock Units | Options Exercise | -10.7% | -6,107 | 50,897 | 18 May 2026 | Direct | ||
| Ming Yan | CTKB | Common Stock | Tax liability | -0.11% | -5,532 | 4,919,617 | 18 May 2026 | Direct | ||
| Ming Yan | CTKB | Common Stock | Options Exercise | 0.45% | 22,179 | 4,934,944 | 18 May 2026 | Direct | ||
| Ming Yan | CTKB | Restricted Stock Units | Options Exercise | -47.5% | -22,179 | 24,552 | 18 May 2026 | Direct | ||
| Philippe Busque | CTKB | Common Stock | Tax liability | -6.86% | -2,685 | 36,448 | 18 May 2026 | Direct | ||
| Philippe Busque | CTKB | Common Stock | Options Exercise | 30.4% | 10,464 | 44,890 | 18 May 2026 | Direct | ||
| Philippe Busque | CTKB | Restricted Stock Units | Options Exercise | -65% | -10,464 | 5,641 | 18 May 2026 | Direct | ||
| Wenbin Jiang | CTKB | Common Stock | Tax liability | -0.47% | -25,542 | 5,428,624 | 18 May 2026 | Direct | ||
| Wenbin Jiang | CTKB | Common Stock | Options Exercise | 1.48% | 80,062 | 5,492,212 | 18 May 2026 | Direct | ||
| Wenbin Jiang | CTKB | Restricted Stock Units | Options Exercise | -67.1% | -80,062 | 39,275 | 18 May 2026 | Direct | ||
| William D. McCombe | CTKB | Common Stock | Tax liability | -8.55% | -9,229 | 98,739 | 18 May 2026 | Direct |
* marks a reported price that did not pass the local price check.