$CTKB

$5.98 +$0.09 (1.53%) Close

$CTKB Overview Financial Statements SEC Filings Executives News Red Flags Capital Raising Ownership Insider Transactions Congressional Trades

Ownership

13F as of Q2 2026 · 130.0M shares outstanding

Who owns CTKB?

By type of holder

Institutions 62.2% Insiders 14.7% Everyone else 23.1%

Concentration Top 10 holders own 52.7%

BlackRock, Inc. 7.4% · Jiang Wenbin 10.4%

Institutional ownership

62.2%

-3.3 pts vs last qtr

Institutional holders

153

-12 vs last qtr

Net shares bought

−4.2M

by institutions in Q2 2026

New / sold out

28 / 40

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

Millennium Management LLC +3.0M
Boston Partners +1.9M

Biggest sellers in Q2 2026

BlackRock, Inc. −7.4M
State Street Corp −1.6M

Who is planning to sell?

Notices of proposed sale, last 12 months

$147K

1 notice from 1 person

Shares covered

31.7K

0.02% of the company

Arranged in advance

of the value is under a 10b5-1 plan

Under a 10b5-1 plan No plan

Largest proposed sellers

Philippe Busque Officer $147K

Every notice on Red Flags →

A Form 144 is notice of a planned sale, not the sale itself. What insiders actually sold is on Insider Transactions.

Is your stake being diluted?

Diluted share count, FY2021–FY2025

+56.7%

+11.88% a year

Each share's claim on the business

−36.2%

shrank without buying or selling a share

Spent on buybacks vs paid in stock

$80.9M vs $96.7M

over 5 fiscal years

Diluted shares, split-adjusted

Buybacks Stock-based comp

How patient are the owners?

Institutional shares by how long they've been held

5+ years0% 3–5 years50% 1–3 years31% Under 1 year18%

Quarterly turnover

19.5%

of institutional shares changed hands

Top 10 managers, median time held

4.8 years

Super Investors

Investment managers reporting CTKB on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
B BlackRock, Inc.	9.6M	7.37%	−7.4M (−43.7%)	2021	0.0%
Shares held by quarter Peak holding18.5M (Q3'24) Change over 8 quarters−8.9M Share of the company7.370% BlackRock, Inc.'s full portfolio →
MM Millennium Management LLC	9.3M	7.18%	+3.0M (+48.4%)	2024	0.0%
Shares held by quarter Peak holding9.3M (Q2'26) Change over 8 quarters+9.1M Share of the company7.180% Millennium Management LLC's full portfolio →

BlackRock, Inc.

9.6M

% of company

7.37%

Change vs last qtr

−7.4M (−43.7%)

Held since

2021

Millennium Management LLC

9.3M

% of company

7.18%

Change vs last qtr

+3.0M (+48.4%)

Held since

2024

28 more super investors behind a free account

See every manager holding Cytek Biosciences, Inc., how their position has changed, and how long they've held it.

Institutional Funds

Mutual funds and ETFs reporting CTKB on Form N-PORT; together they hold 31.0% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
IC iShares Core S&P Small-Cap ETF iShares Trust	$28.8M	6.6M	5.07%	0.03%	March 31, 2026
VT Vanguard Total Stock Market Index Fund Vanguard Index Funds	$15.6M	3.5M	2.71%	0.00%	June 30, 2026

iShares Core S&P Small-Cap ETF

iShares Trust

Position value

$28.8M

% of company

5.07%

% of the fund

0.03%

As of

March 31, 2026

Vanguard Total Stock Market Index Fund

Vanguard Index Funds

Position value

$15.6M

% of company

2.71%

% of the fund

0.00%

As of

June 30, 2026

23 more funds behind a free account

See every fund holding Cytek Biosciences, Inc. and how much of the fund the position is.

Insiders and 5%+ holders

From Forms 3/4/5 and Schedules 13D/G

Holder	Shares	% of company	Change vs last qtr	8 quarters	Held since	% of their book
JW Jiang Wenbin Insider	13.6M	10.43%	—	—	—	—
Insider holdings come from Form 3/4/5 filings, which are not quarterly. Share of the company10.430% Jiang Wenbin's insider activity →
YM Yan Ming Insider	4.8M	3.71%	—	—	—	—
Insider holdings come from Form 3/4/5 filings, which are not quarterly. Share of the company3.710% Yan Ming's insider activity →

Jiang Wenbin

Insider

13.6M

% of company

10.43%

Change vs last qtr

—

Held since

—

Yan Ming

Insider

4.8M

% of company

3.71%

Change vs last qtr

—

Held since

—

11 more holders behind a free account

See every insider and 5%+ holder of Cytek Biosciences, Inc..

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