Cytek Biosciences
CTKB
155 hedge funds and large institutions have $414M invested in Cytek Biosciences in 2025 Q4 according to their latest regulatory filings, with 21 funds opening new positions, 52 increasing their positions, 61 reducing their positions, and 15 closing their positions.
100% more funds holding in top 10
Funds holding in top 10: 1 → 2 (+1)
40% more first-time investments, than exits
New positions opened: 21 | Existing positions closed: 15
36% more call options, than puts
Call options by funds: $38K | Put options by funds: $28K
34% more capital invested
Capital invested by funds: $309M → $414M (+$106M)
1% more funds holding
Funds holding: 153 → 155 (+2)
1.27% more ownership
Funds ownership: 62.88% → 64.15% (+1.3%)
15% less repeat investments, than reductions
Existing positions increased: 52 | Existing positions reduced: 61
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Boston Partners
Boston,
Massachusetts
|
+$23.1M |
| 2 |
Millennium Management
New York
|
+$6.19M |
| 3 |
Russell Investments Group
London,
United Kingdom
|
+$3.91M |
| 4 |
Bank of America
Charlotte,
North Carolina
|
+$3.19M |
| 5 |
BlackRock
New York
|
+$2.9M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
BCM
Brown Capital Management
Baltimore,
Maryland
|
-$13.4M |
| 2 |
Wellington Management Group
Boston,
Massachusetts
|
-$8.25M |
| 3 |
Dimensional Fund Advisors
Austin,
Texas
|
-$2.65M |
| 4 |
Jacobs Levy Equity Management
Florham Park,
New Jersey
|
-$2.6M |
| 5 |
New York State Common Retirement Fund
Albany,
New York
|
-$1.38M |
CTKB Hedge Fund Activity: Q4 2025 in Review
155 of the 8,267 institutional investors tracked by Wall St. Rank reported a position in Cytek Biosciences (CTKB) for Q4 2025, worth a combined $414M — up 34% from $309M a quarter earlier.
Buyers outnumbered sellers: 21 funds opened new CTKB positions and 15 closed out — a net gain of 6 holders — while 52 added to existing stakes and 61 trimmed.
The largest buyer was Boston Partners, adding an estimated $23.1M. The largest seller was Brown Capital Management, cutting an estimated $13.4M.
- 155 institutional investors held Cytek Biosciences (CTKB) as of Q4 2025, up from 153 in Q3 2025.
- Funds reported $414M of Cytek Biosciences stock for Q4 2025, up 34% quarter-over-quarter.
- 21 funds opened new Cytek Biosciences positions in Q4 2025 and 15 closed out, a net change of +6 holders.
- The largest Cytek Biosciences buyer in Q4 2025 was Boston Partners, an estimated $23.1M added.
- The largest Cytek Biosciences seller in Q4 2025 was Brown Capital Management, an estimated $13.4M sold.
Based on aggregated 13F filings for Q4 2025.