Who owns CTKB?
Institutional ownership of Cytek Biosciences Inc. from Form 13F, Q2 2026
155 institutional managers reported holding Cytek Biosciences Inc. (CTKB) in Form 13F filings for Q2 2026, with 81,520,227 shares worth $361M. The largest reported holder was BlackRock, Inc. Managers that filed both quarters cut a net 3,487,684 shares (-4.1%). 28 opened new positions and 37 sold out.
- Funds holding
- 155
- Value held
- $361M
- New / sold out
- 28 / 37
- Net shares, same filers
- -4.1%
Holdings as of June 30, 2026, the end of Q2 2026. Managers have 45 days after a quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.
Largest holders of CTKB
| Fund | Value | Share of 13F holdings | Shares | Move |
|---|---|---|---|---|
| BlackRock, Inc. | $42.4M | 11.8% | 9,578,643 | Trimmed |
| Millennium Management LLC | $41.4M | 11.5% | 9,338,010 | Added |
| Boston Partners | $33.9M | 9.4% | 7,660,943 | Added |
| HHLR Advisors, LTD. | $29.5M | 8.2% | 6,657,030 | Unchanged |
| Topline Capital Management, LLC | $27.8M | 7.7% | 6,283,450 | Trimmed |
| Vanguard Capital Management LLC | $21.9M | 6.1% | 4,939,597 | Added |
| Geode Capital Management, LLC | $13.6M | 3.8% | 3,059,573 | Added |
| Dimensional Fund Advisors LP | $11.6M | 3.2% | 2,616,257 | Trimmed |
| State Street Corp | $11.4M | 3.1% | 2,566,121 | Trimmed |
| Goldman Sachs Group Inc | $9.6M | 2.7% | 2,167,515 | Trimmed |
| Royce & Associates LP | $9.2M | 2.6% | 2,081,579 | Added |
| Russell Investments Group, Ltd. | $6.7M | 1.9% | 1,511,315 | Added |
| Acadian Asset Management LLC | $6.1M | 1.7% | 1,376,048 | Added |
| Bank of America Corp | $5.8M | 1.6% | 1,315,332 | Added |
| Vanguard Portfolio Management LLC | $5.1M | 1.4% | 1,141,592 | Trimmed |
| Charles Schwab Investment Management Inc | $4.8M | 1.3% | 1,073,253 | Trimmed |
| Northern Trust Corp | $4.4M | 1.2% | 1,003,294 | Trimmed |
| HRT Financial LP | $4.4M | 1.2% | 997,769 | Added |
| Arrowstreet Capital, Limited Partnership | $4.3M | 1.2% | 973,833 | Added |
| Jane Street Group, LLC | $4.0M | 1.1% | 906,162 | New |
| Tudor Investment Corp Et Al | $3.7M | 1.0% | 837,913 | Added |
| AQR Capital Management LLC | $3.6M | 1.0% | 813,971 | Trimmed |
| Vanguard Fiduciary Trust Co | $3.3M | 0.9% | 740,662 | Added |
| Citadel Advisors LLC | $3.2M | 0.9% | 721,470 | Added |
| Morgan Stanley | $3.1M | 0.9% | 701,792 | Trimmed |
Share of 13F holdings is each fund's shares as a share of the 81,520,227 CTKB shares all 13F filers reported, not of shares outstanding.
Biggest buyers in Q2 2026
- Millennium Management LLC Added+$13.5M
- Boston Partners Added+$8.2M
- Acadian Asset Management LLC Added+$4.3M
- Jane Street Group, LLC New+$4.0M
- Qube Research & Technologies Ltd New+$3.1M
- Arrowstreet Capital, Limited Partnership Added+$2.9M
- Susquehanna International Group, LLP Added+$2.8M
- HRT Financial LP Added+$2.6M
- Tudor Investment Corp Et Al Added+$2.3M
- Marshall Wace, LLP New+$2.0M
Biggest sellers in Q2 2026
- BlackRock, Inc. Trimmed-$32.9M
- State Street Corp Trimmed-$6.9M
- Brown Capital Management LLC Sold out-$6.5M
- Vanguard Portfolio Management LLC Trimmed-$5.2M
- Morgan Stanley Trimmed-$4.5M
- Simcoe Capital LLC Sold out-$3.9M
- Topline Capital Management, LLC Trimmed-$3.5M
- CenterBook Partners LP Trimmed-$2.6M
- Principal Financial Group Inc Sold out-$2.3M
- Public Sector Pension Investment Board Sold out-$1.7M
The change in shares since the quarter before, adjusted for stock splits and priced at the Q2 2026 value per share. Funds bought $66.9M and sold $82.1M; 44 added and 65 trimmed.
Schedule 13D and 13G filings on CTKB
Owners of more than 5% must file within days, so these can be newer than the 13F data.
- 2026-08-04Boston Partners SCHEDULE 13G filed by Cytek Biosciences Inc.Schedule 13G
- 2026-04-09MILLENNIUM MANAGEMENT LLC SCHEDULE 13G filed by Cytek Biosciences Inc.Schedule 13G
- 2025-11-17Topline Capital Management, LLC SCHEDULE 13G filed by Cytek Biosciences Inc.Schedule 13G
Questions about CTKB ownership
- Who owns CTKB stock?
- 155 institutional investment managers reported CTKB positions in their Form 13F filings for Q2 2026, holding 81,520,227 shares worth $361M in total. BlackRock, Inc. reported the largest position.
- Are funds buying or selling CTKB?
- In Q2 2026, 28 managers opened new CTKB positions, 44 added, 65 trimmed and 37 sold out. Managers that filed in both quarters sold a net 3,487,684 shares.
- How current is this CTKB institutional ownership data?
- It covers holdings as of the end of Q2 2026. Managers have 45 days after the quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.
From the SEC's Form 13F data sets for Q2 2026: every 13F holdings report, matched to CTKB by CUSIP. Options are left out. CTKB news and filings · CTKB insider trades · Top funds