CTKB Cytek Biosciences, Inc.

NASDAQ
$4.61

Cytek Biosciences, Inc. (CTKB) Institutional Ownership

What the institutions did with CTKB last quarter, from their 13F filings. Counting managers rather than shares is the point: a single index fund adding to a position tells you far less than four hundred separate managers all deciding to. Positions as reported for the quarter ended June 30, 2026.

Managers compared
191
filed both this quarter and last
Managers holding
153
-11 on the quarter
Buyers
72
27 opened new
Sellers
103
38 sold out entirely
Buyer share
41.1%
of managers who traded it
Breadth
-17.7
net buyers, as a share of those trading

Every manager below opens. Subscribers can see any firm's whole portfolio — every position, its weight, and what they bought, trimmed and exited last quarter.

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Ownership map

Each block is one manager, sized by shares held and colored by how much they moved the position last quarter. Green added, red cut, grey stood pat.

Cut Unchanged Added Color saturates at ±50%.

Largest holders

Manager Shares % of reported
BlackRock, Inc. 9.6M 11.8%
MILLENNIUM MANAGEMENT LLC 9.3M 11.5%
Boston Partners 7.7M 9.4%
HHLR ADVISORS, LTD. 6.7M 8.2%
Topline Capital Management, LLC 6.3M 7.7%
VANGUARD CAPITAL MANAGEMENT LLC 4.9M 6.1%
GEODE CAPITAL MANAGEMENT, LLC 3.1M 3.8%
DIMENSIONAL FUND ADVISORS LP 2.6M 3.2%
STATE STREET CORP 2.6M 3.1%
GOLDMAN SACHS GROUP INC 2.2M 2.7%
ROYCE & ASSOCIATES LP 2.1M 2.6%
Russell Investments Group, Ltd. 1.5M 1.9%
ACADIAN ASSET MANAGEMENT LLC 1.4M 1.7%
BANK OF AMERICA CORP /DE/ 1.3M 1.6%
VANGUARD PORTFOLIO MANAGEMENT LLC 1.1M 1.4%
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 1.1M 1.3%
NORTHERN TRUST CORP 1.0M 1.2%
HRT FINANCIAL LP 997.8K 1.2%
ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 973.8K 1.2%
JANE STREET GROUP, LLC 906.2K 1.1%
TUDOR INVESTMENT CORP ET AL 837.9K 1.0%
AQR CAPITAL MANAGEMENT LLC 814.0K 1.0%
VANGUARD FIDUCIARY TRUST CO 740.7K 0.9%
CITADEL ADVISORS LLC 721.5K 0.9%
MORGAN STANLEY 701.8K 0.9%

Largest changes

Manager Action Previous Current Change
BlackRock, Inc. Reduced 17.0M 9.6M -7.4M
MILLENNIUM MANAGEMENT LLC Increased 6.3M 9.3M +3.0M
Boston Partners Increased 5.8M 7.7M +1.9M
STATE STREET CORP Reduced 4.1M 2.6M -1.6M
BROWN CAPITAL MANAGEMENT LLC Sold Out 1.5M 0 -1.5M
VANGUARD PORTFOLIO MANAGEMENT LLC Reduced 2.3M 1.1M -1.2M
MORGAN STANLEY Reduced 1.7M 701.8K -1.0M
ACADIAN ASSET MANAGEMENT LLC Increased 399.0K 1.4M +977.1K
JANE STREET GROUP, LLC New 0 906.2K +906.2K
Simcoe Capital LLC Sold Out 882.1K 0 -882.1K
Topline Capital Management, LLC Reduced 7.1M 6.3M -781.0K
Qube Research & Technologies Ltd New 0 689.8K +689.8K
ARROWSTREET CAPITAL, LIMITED PARTNERSHIP Increased 319.9K 973.8K +653.9K
SUSQUEHANNA INTERNATIONAL GROUP, LLP Increased 56.0K 681.7K +625.7K
HRT FINANCIAL LP Increased 414.1K 997.8K +583.7K
CenterBook Partners LP Reduced 729.9K 149.2K -580.7K
PRINCIPAL FINANCIAL GROUP INC Sold Out 534.8K 0 -534.8K
TUDOR INVESTMENT CORP ET AL Increased 320.7K 837.9K +517.2K
MARSHALL WACE, LLP New 0 441.7K +441.7K
ROYCE & ASSOCIATES LP Increased 1.6M 2.1M +439.2K
Point72 Asset Management, L.P. New 0 422.4K +422.4K
Jain Global LLC New 0 411.5K +411.5K
D. E. Shaw & Co., Inc. Increased 260.1K 669.2K +409.1K
Public Sector Pension Investment Board Sold Out 394.7K 0 -394.7K
BANK OF AMERICA CORP /DE/ Increased 1.0M 1.3M +306.3K
CITADEL ADVISORS LLC Increased 471.4K 721.5K +250.1K
Bank of New York Mellon Corp Reduced 608.6K 371.4K -237.2K
GEODE CAPITAL MANAGEMENT, LLC Increased 2.8M 3.1M +225.6K
FMR LLC Increased 283.4K 504.4K +221.0K
Invesco Ltd. Reduced 388.2K 185.7K -202.6K
Y-Intercept (Hong Kong) Ltd New 0 193.1K +193.1K
GOLDMAN SACHS GROUP INC Reduced 2.3M 2.2M -177.2K
VANGUARD CAPITAL MANAGEMENT LLC Increased 4.8M 4.9M +176.7K
AMERIPRISE FINANCIAL INC Reduced 187.3K 14.1K -173.1K
Legal & General Group Plc Reduced 182.9K 11.8K -171.1K
JPMORGAN CHASE & CO Reduced 299.1K 141.9K -157.2K
Russell Investments Group, Ltd. Increased 1.4M 1.5M +151.4K
XTX Topco Ltd New 0 142.7K +142.7K
TWO SIGMA INVESTMENTS, LP Increased 25.6K 168.2K +142.6K
BNP PARIBAS FINANCIAL MARKETS Increased 78.0K 215.0K +137.0K
Jump Financial, LLC Increased 28.9K 148.1K +119.2K
STATE OF WISCONSIN INVESTMENT BOARD Sold Out 104.0K 0 -104.0K
RHUMBLINE ADVISERS Reduced 254.6K 153.2K -101.4K
AQR CAPITAL MANAGEMENT LLC Reduced 912.3K 814.0K -98.4K
UBS Group AG Reduced 186.9K 88.9K -98.0K
PRUDENTIAL FINANCIAL INC Reduced 117.6K 23.3K -94.3K
Aquatic Capital Management LLC New 0 76.8K +76.8K
Thrivent Financial for Lutherans Sold Out 73.4K 0 -73.4K
VOYA INVESTMENT MANAGEMENT LLC Reduced 141.4K 74.0K -67.4K
Catalyst Funds Management Pty Ltd New 0 62.5K +62.5K
LOS ANGELES CAPITAL MANAGEMENT LLC New 0 62.2K +62.2K
Illinois Municipal Retirement Fund Sold Out 60.9K 0 -60.9K
GSA CAPITAL PARTNERS LLP Increased 109.1K 167.6K +58.5K
Squarepoint Ops LLC Increased 25.3K 82.8K +57.5K
WELLS FARGO & COMPANY/MN Increased 45.3K 102.7K +57.4K
State of Alaska, Department of Revenue Reduced 61.3K 6.5K -54.8K
Balyasny Asset Management L.P. New 0 54.4K +54.4K
IEQ CAPITAL, LLC Reduced 144.4K 90.1K -54.3K
PANAGORA ASSET MANAGEMENT INC Sold Out 51.6K 0 -51.6K
Louisiana State Employees Retirement System Sold Out 48.8K 0 -48.8K

13F filings are due 45 days after quarter end and cover long positions in U.S.-listed equities only, so this is a lagged and partial picture: shorts, bonds and foreign listings never appear. Options positions are excluded here rather than folded into the share counts. Political ownership is coming.