RPID · Rapid Micro Biosystems, Inc.

$1.57 -0.04 (-2.48%) At close · Aug 28

Market Cap

$78.50M

50.16M

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Quarter:

Holders: 33

Total Value: $30,108,438

Total Shares: 17,403,731

Institutional Ownership Trend

20 quarters

Holder Concentration

Across 33 13F filers · Δ vs Mar 31, 2026

Top Holder

48.5%

−4.8 pts

Top 5

86.8%

+6.6 pts

Top 10

94.9%

+5.1 pts

HHI

2,884

Highly concentrated−195

Quarterly Activity

vs Mar 31, 2026

New

Increased

Decreased

Sold Out

Unchanged

Holder count: -13

Institutional value: -16.3%

Shares held: +9.9%

Top Buyers

vs Mar 31, 2026

Institution	Added	Now Holds
Large RENAISSANCE TECHNOLOGIES LLC	+85,484	212,101
Small Evernest Financial Advisors, LLC	+73,490	506,000
Mega BlackRock, Inc.	+32,600	189,832
Mid XTX Topco Ltd	+18,657	79,727
Mega DIMENSIONAL FUND ADVISORS LP	+16,603	104,192

Top Sellers

vs Mar 31, 2026

Institution	Sold	Now Holds
Small ESSEX INVESTMENT MANAGEMENT CO LLC	−521,235	362,696
Large SEI INVESTMENTS CO	−217,947	66,869
Large Advent International, L.P.	−172,583	379,794
Mega JANE STREET GROUP, LLC	−106,994	25,931
Mega MILLENNIUM MANAGEMENT LLC	−46,681	236,599

Top New Positions

vs Mar 31, 2026

Institution	Acquired	Value (USD)
Mid ARMISTICE CAPITAL, LLC	3,328,000	$5,757,440
Large HRT FINANCIAL LP	23,093	$39,950
Mega CITADEL ADVISORS LLC	16,142	$27,925
Mid Tower Research Capital LLC (TRC)	1,900	$3,287
Small Caitong International Asset Management Co., Ltd	35	$60

Top Sold-Out Positions

vs Mar 31, 2026

Institution	Previously Held	Last Value (USD)
Small Legato Capital Management LLC	274,924	$624,077
Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP	212,114	$481,498
Mid 683 Capital Management, LLC	120,773	$274,154
Mega GOLDMAN SACHS GROUP INC	71,912	$163,240
Micro FIFTH LANE CAPITAL, LP	71,000	$161,170

Filter: New 5 Increased 9 Reduced 12 Sold out 18 Unchanged 7

Showing 33 of 33

All Common Calls Puts

Compact Export CSV

Holder

Value (USD)

% of 13F

Bain Capital Life Sciences Investors, LLC

$14,591,788

48.46%

8,434,560

ARMISTICE CAPITAL, LLC

$5,757,440

19.12%

3,328,000

ABG-WTT Global Life Science Capital Partners GP Ltd

$3,197,552

10.62%

1,848,296

VANGUARD CAPITAL MANAGEMENT LLC

$1,698,918

5.64%

982,034

Evernest Financial Advisors, LLC

$875,380

2.91%

506,000

Advent International, L.P.

$657,043

2.18%

379,794

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Advent Global Opportunities Management LLC	379,794	$657,043	100.0%	Defined

ESSEX INVESTMENT MANAGEMENT CO LLC

$627,464

2.08%

362,696

MILLENNIUM MANAGEMENT LLC

$409,316

1.36%

236,599

GEODE CAPITAL MANAGEMENT, LLC

$394,510

1.31%

228,041

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
GEODE CAPITAL MANAGEMENT TRUST COMPANY, LLC	43,813	$75,796	19.2%	Defined
Held directly	184,228	$318,714	80.8%	Defined

RENAISSANCE TECHNOLOGIES LLC

$366,934

1.22%

212,101

BlackRock, Inc.

$328,408

1.09%

189,832

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
BlackRock Investment Management, LLC	7,524	$13,016	4.0%	Sole
BlackRock Fund Advisors	112,127	$193,979	59.1%	Sole
BlackRock Institutional Trust Company, N.A.	70,181	$121,413	37.0%	Sole

VANGUARD FIDUCIARY TRUST CO

$191,137

0.63%

110,484

DIMENSIONAL FUND ADVISORS LP

$180,250

0.60%

104,192

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Dimensional Fund Advisors Ltd.	2,975	$5,146	2.9%	Defined
Dimensional Ireland Ltd	21,549	$37,279	20.7%	Defined
Held directly	79,668	$137,825	76.5%	Sole

STATE STREET CORP

$162,402

0.54%

93,874

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
STATE STREET GLOBAL ADVISORS TRUST COMPANY	93,874	$162,402	100.0%	Defined

XTX Topco Ltd

$137,927

0.46%

79,727

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
XTX EXECUTION SERVICES LLC joint	79,727	$137,927	100.0%	Defined

SEI INVESTMENTS CO

$115,683

0.38%

66,869

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
SEI TRUST CO	66,869	$115,683	100.0%	Sole

NORTHERN TRUST CORP

$72,843

0.24%

42,106

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
NORTHERN TRUST CO joint	42,106	$72,843	100.0%	Defined

ALGERT GLOBAL LLC

$66,271

0.22%

38,307

MORGAN STANLEY

$47,725

0.16%

27,587

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
MORGAN STANLEY SMITH BARNEY LLC	27,587	$47,725	100.0%	Defined

JANE STREET GROUP, LLC

$44,860

0.15%

25,931

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Jane Street Capital, LLC	21,546	$37,274	83.1%	Defined
Jane Street Global Trading, LLC	4,385	$7,586	16.9%	Defined

HRT FINANCIAL LP

$39,950

0.13%

23,093

CITADEL ADVISORS LLC

$27,925

0.09%

16,142

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Citadel Securities GP LLC	16,142	$27,925	100.0%	Defined

OSAIC HOLDINGS, INC.

$24,739

0.08%

14,300

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
OSAIC WEALTH, INC.	14,300	$24,739	100.0%	Defined

NANO CAP NEW MILLENNIUM GROWTH FUND L P

$21,625

0.07%

12,500

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
AZG TANGIBLE ASSETS FUND LLC	12,500	$21,625	100.0%	Sole

AMERICAN CENTURY COMPANIES INC

$20,133

0.07%

11,638

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
AMERICAN CENTURY INVESTMENT MANAGEMENT INC	11,638	$20,133	100.0%	Defined

Vanguard Global Advisers, LLC

$20,119

0.07%

11,630

Larson Financial Group LLC

$14,523

0.05%

8,395

UBS Group AG

$11,430

0.04%

6,607

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
UBS AG	6,607	$11,430	100.0%	Defined

Tower Research Capital LLC (TRC)

$3,287

0.01%

1,900

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Latour Trading LLC (Latour)	1,900	$3,287	100.0%	Defined

BARCLAYS PLC

$583

0.00%

337

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
BARCLAYS CAPITAL INC.	337	$583	100.0%	Defined

JPMORGAN CHASE & CO

$188

0.00%

109

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
J.P. Morgan Securities plc	109	$188	100.0%	Defined

Caitong International Asset Management Co., Ltd

$60

0.00%

SBI Securities Co., Ltd.

$25

0.00%

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
SUSQUEHANNA SECURITIES, LLC	212,114	$481,498	100.0%	Other

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
683 Capital Partners, LP	120,773	$274,154	100.0%	Defined

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
GOLDMAN SACHS & CO. LLC	71,912	$163,240	100.0%	Defined

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
BANK OF AMERICA NA	31,014	$70,401	100.0%	Defined

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Fullerton Fund Investments Pte Ltd	21,818	$49,526	100.0%	Defined

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Marshall Wace North America L.P. joint	15,224	$34,558	100.0%	Other

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Garanti Asset Management	12,691	$28,808	100.0%	Defined

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Hudson Bay Capital UK LLP	12,524	$28,429	100.0%	Defined

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
RBC Capital Markets, LLC	719	$1,632	100.0%	Defined

Key facts CIK 1380106 CUSIP 75340L104 13F (30d) 34 filings 33 filers Visit website Investor relations