Stocks › CTKB

Cytek Biosciences CTKB

US equityMarket cap rank #3517

$5.34 −$0.04 (-0.74%)

Pre-market · Oct 8, 8:20 am ET · After hours $5.34 0.00%

Open$5.21

Prev close$5.38

Day range$5.11 – $5.34

Volume1.78M

Market cap$694.11M

P/E (TTM)–

Dividend yield–

Ownership & positioning

Who holds it, who is betting against it, and where the big money is moving

Institutional ownership63.4%-0.34 pts vs. prior quarter

Institutions holding184-1 vs. prior quarter

Insider trades (recent)37 buys / 13 sellsNet buying

Short interest4.03% of floatDays to cover 5.7 · as of 15 Sep 2026

Short-sale volume share18.5%5-day average of daily volume

Short-sale volume as % of daily volume

Large-order net flow, last 20 sessions

Net of large-order buying minus selling, in USD. Over this window: −$6.09M (3 inflow days, 17 outflow days).

Net flow by order size, last 20 sessions

Super/Big orders approximate institutional-size trades; Mid/Small approximate retail-size trades. Net buy minus sell value in each bucket, summed over the window.

The five largest holders on file together own 30.4% of shares outstanding.

Largest holders

BlackRock7.37%
Millennium Management LLC7.18%
Boston Partners Global Investors, Inc.5.87%
Hillhouse Capital Management, Ltd.5.12%
Topline Capital Management, LLC4.83%
Vanguard Capital Management, LLC4.37%
Wenbin Jiang4.28%
Ming Yan3.71%

By investor type

Mutual Fund37.80%
Hedge Fund16.76%
Individual/Insider8.48%
VC/PE Fund5.12%
Private Company2.31%
Public Company1.06%
Insurance Company0.20%
Government Pension Fund0.15%

Reported short interest has risen from 2.72% to 4.03% of float over the last 6 biweekly reports (30 Jun 2026 to 15 Sep 2026).

Recent institutional activity

Holder	Type	Period	Share change	New stake
Nuveen Asset Management LLC	Insurance Company	2026/Q3	+257,085	0.2%
Millennium Management LLC	Hedge Fund	2026/Q3	+3,046,212	7.2%
Boston Partners Global Investors, Inc.	Mutual Fund	2026/Q3	+1,832,372	5.9%
Acadian Asset Management LLC	Mutual Fund	2026/Q3	+977,060	1.1%
Jane Street Group, LLC	Private Company	2026/Q3	+906,162	0.7%
Qube Research & Technologies Ltd	Mutual Fund	2026/Q3	+689,821	0.5%
Arrowstreet Capital, Limited Partnership	Mutual Fund	2026/Q3	+653,924	0.7%
Susquehanna International Group, LLP	Private Company	2026/Q3	+625,695	0.5%
Hudson River Trading LLC	Private Company	2026/Q3	+583,717	0.8%
Goldman Sachs Asset Management, L.P.	Mutual Fund	2026/Q3	+549,050	1.4%
Tudor Investment Corporation	Hedge Fund	2026/Q3	+517,198	0.6%
Marshall Wace LLP	Hedge Fund	2026/Q3	+441,704	0.3%
Royce & Associates, LP	Mutual Fund	2026/Q3	+439,211	1.6%
Point72 Asset Management, L.P.	Hedge Fund	2026/Q3	+422,361	0.3%
Jain Global LLC	Hedge Fund	2026/Q3	+411,465	0.3%

Institutional buy/sell activity by reporting period, largest moves first.

Insider transactions

Date	Insider	Title	Transaction	Shares	Price	Held after
1 Sep 2026	Philippe Busque	Senior Vice President of Global Sales & Services	Intent to Sell (Form 144)	-31,666	$4.63	–
17 Aug 2026	Glenn Muir	Independent Director	Derivative Exercise and Retained	+3,086	–	3,086
17 Aug 2026	Richard Chin	Independent Director	Derivative Exercise and Retained	+6,107	–	28,499
17 Aug 2026	Michael Holder	Independent Director	Derivative Exercise and Retained	+2,181	–	62,875
17 Aug 2026	William McCombe	Chief Financial Officer	Derivative Exercise and Sale	-11,904	$4.67	134,693
17 Aug 2026	William McCombe	Chief Financial Officer	Derivative Exercise and Retained	+23,516	–	134,693
17 Aug 2026	Wenbin Jiang	Chairperson & CEO	Derivative Exercise and Sale	-36,269	$4.67	5,561,029
17 Aug 2026	Wenbin Jiang	Chairperson & CEO	Derivative Exercise and Retained	+83,826	–	5,561,029
17 Aug 2026	Ming Yan	CTO & Director	Derivative Exercise and Sale	-8,088	$4.67	4,821,870
17 Aug 2026	Ming Yan	CTO & Director	Derivative Exercise and Retained	+25,182	–	4,821,870
9 Aug 2026	Ilan Feuchtwang		Other Derivative Acquisition	+127,118	$4.66	127,118
9 Aug 2026	Ilan Feuchtwang		Other Derivative Acquisition	+241,416	–	241,416
11 Jun 2026	Ming Yan	CTO & Director	Other Disposition	-135,892	–	4,796,688
9 Jun 2026	Deborah Neff	Independent Director	Other Derivative Acquisition	+18,261	$4.05	18,261
9 Jun 2026	Deborah Neff	Independent Director	Other Derivative Acquisition	+33,333	–	33,333
9 Jun 2026	Deborah Neff	Independent Director	Derivative Exercise and Retained	+43,973	–	59,679
9 Jun 2026	Glenn Muir	Independent Director	Other Derivative Acquisition	+29,835	$4.05	29,835
9 Jun 2026	Glenn Muir	Independent Director	Other Derivative Acquisition	+55,555	–	55,555
9 Jun 2026	Jack Ball	Lead Independent Director	Derivative Exercise and Retained	+43,973	–	86,678
9 Jun 2026	Richard Chin	Independent Director	Other Derivative Acquisition	+18,261	$4.05	18,261

From Form 4/Form 144 filings. Negative share counts are disposals (sales, gifts, or shares withheld for taxes); positive are acquisitions.

Short interest, by report

Report date	Shares short	% of float	Days to cover
15 Sep 2026	5,242,079	4.0%	5.7
31 Aug 2026	4,931,028	3.8%	6.6
14 Aug 2026	4,989,610	3.8%	5.1
31 Jul 2026	4,895,239	3.8%	7.5
15 Jul 2026	5,029,578	3.9%	5.5
30 Jun 2026	3,507,190	2.7%	1.0

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