Rapid Micro Biosystems RPID Insider Ownership

NASDAQ RPID

$0.77 0.00 (-0.25%)

At close: Oct 20, 2026 · 4:00 PM EDT

Insider Holdings by Owner

5.71Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026

Insider Ownership

29.93%

▼-2.95% pp QoQ

Shares Held by Insiders

14.96Mn

filed for Sep 2026

▼-8.98% QoQ

Shares Outstanding

49.97Mn

49,965,634 shares

Direct Holdings

2.49Mn

Indirect: 12.46Mn

Net Shares Traded (QoQ)

-1.48Mn

net selling in Sep 2026

Insiders Holding Shares

with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Insiders

Bought Sold

Latest quarter —

Net over range —

Buying quarters —

Insider Ownership Summary

Updated Oct 10, 2026

Over the past 12 months, Rapid Micro Biosystems insiders sold $1.14 million of stock on the open market (277.2K shares) and made no open-market purchases.

Rapid Micro Biosystems' open-market sales in the past 12 months came from 4 insiders; no insider bought.
Longitude Capital Partners II, LLC (10% owner) sold the most Rapid Micro Biosystems stock on the open market over the past 12 months, $663,949 (157.74K shares), most recently on February 4, 2026.
The latest open-market trade in RPID stock by an insider was a sale of 9.6K shares for $41,467 by John J. Addington Wilson (Chief Operating Officer) on March 11, 2026.
Beyond open-market trades, insiders at Rapid Micro Biosystems received 467.09K shares in stock awards, acquired 646.02K shares through option exercises and conversions, gave up 6.85K shares to cover taxes or exercise prices and gave away 40K shares as gifts in the last 12 months.
According to Business Quant data, insiders at Rapid Micro Biosystems reported 14.96Mn shares in total in their latest Form 4 filings, down 4.24% from 15.62Mn shares at the end of Q3 2025.
Indirect holdings, through trusts, partnerships, family members and other entities, make up 83.34% (12.46Mn shares) of Rapid Micro Biosystems' insider total, with the other 16.66% (2.49Mn shares) held directly.
The insider holdings in Rapid Micro Biosystems belong to 11 insiders who have reported on Form 4 within the past two years.
Rapid Micro Biosystems' top three insider holders by shares held are Bain Capital Life Sciences Investors, LLC (10% owner, 8.43Mn shares), Longitude Capital Partners II, LLC (10% owner, 4.03Mn shares) and Robert G. Spignesi Jr. (President and CEO, 1.19Mn shares).
Of the shares held by RPID insiders, 56.40% belong to Bain Capital Life Sciences Investors, LLC.
Institutional holders reported 34.83% of Rapid Micro Biosystems' outstanding shares for Q2 2026; insiders' latest Form 4 filings put their stake at about 29.93%, and other investors, including the public, hold the remaining 35.24%.
In the last 12 months, 30 Form 4 filings with transactions in RPID stock came from 11 insiders.
The insider holdings and trades above for Rapid Micro Biosystems reflect Form 4 filings through July 24, 2026.

Form 4 Holdings

Insiders Holding RPID

Insiders 15

Shares held 5.71Mn

Of outstanding 11.43%

#	Insider	Position	Direct	Indirect	Total	Share of Insiders	Last Filed
1	Lewis Management Lp Kennedy	TenPercentOwner	0	2,904,490	2,904,490	50.9%	06 Jun, 2022
2	Robert G. Jr. Spignesi	President And Ceo	1,191,973	0	1,191,973	20.9%	24 Jul, 2026
3	Sean M Wirtjes	Chief Financial Officer	568,981	0	568,981	10.0%	02 Jun, 2026
4	John J. Addington Wilson	Chief Operating Officer	316,762	0	316,762	5.5%	12 Mar, 2026
5	Richard S Kollender	Director	133,826	0	133,826	2.3%	24 Jul, 2026
6	Jonathan Paris	Svp, General Counsel	128,698	0	128,698	2.3%	13 Mar, 2023
7	Victoria Vezina	Chief Human Resources Officer	112,608	0	112,608	2.0%	12 Mar, 2024
8	Melinda Litherland Pei	Director	100,687	0	100,687	1.8%	02 Jun, 2026
9	Inese Lowenstein	Director	70,687	0	70,687	1.2%	02 Jun, 2026
10	Kirk Malloy	Director	60,687	0	60,687	1.1%	02 Jun, 2026
11	Richard A Keys	Chief Commercial Officer	43,750	0	43,750	0.8%	15 Feb, 2022
12	Natale S Ricciardi	Director	29,442	0	29,442	0.5%	02 Mar, 2026
13	Dafni Bika	Director	19,300	0	19,300	0.3%	26 May, 2026
14	Jeffrey Lawrence Schwartz	Director, TenPercentOwner	14,300	0	14,300	0.3%	28 May, 2024
15	David Hirsch	Director	14,300	0	14,300	0.3%	28 May, 2024

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

262 Insider Transactions

Source SEC Form 4

Latest quarter Sep 2026

Date	Insider	Position	Transaction	Shares	Price	Value	Shares Held After	Ownership
24 Jul, 2026	Richard S Kollender	Director	Acquired M	1,681	$0.75	$1.26K	131,999	Direct
22 Jul, 2026	Robert G. Jr. Spignesi	President And Ceo	Acquired M	1,402	$0.75	$1.05K	1,191,973	Direct
22 Jul, 2026	Robert G. Jr. Spignesi	President And Ceo	Disposed M	1,402	$0.00	$0	0	Direct
24 Jul, 2026	Richard S Kollender	Director	Acquired M	1,827	$0.75	$1.37K	133,826	Direct
24 Jul, 2026	Richard S Kollender	Director	Disposed M	1,681	$0.00	$0	0	Direct
24 Jul, 2026	Richard S Kollender	Director	Disposed M	1,827	$0.00	$0	0	Direct
29 May, 2026	Melinda Litherland Pei	Director	Acquired A	12,787	$1.96	$25.00K	100,687	Direct
29 May, 2026	Inese Lowenstein	Director	Acquired A	12,787	$1.96	$25.00K	70,687	Direct
29 May, 2026	Kirk Malloy	Director	Acquired A	12,787	$1.96	$25.00K	60,687	Direct
29 May, 2026	Robert G. Jr. Spignesi	President And Ceo	Acquired A	12,787	$1.96	$25.00K	1,190,571	Direct
29 May, 2026	Sean M Wirtjes	Chief Financial Officer	Acquired A	12,787	$1.96	$25.00K	568,981	Direct
29 May, 2026	Sean M Wirtjes	Chief Financial Officer	Acquired A	12,787	$0.00	$0	12,787	Direct
29 May, 2026	Melinda Litherland Pei	Director	Acquired A	12,787	$0.00	$0	12,787	Direct
29 May, 2026	Robert G. Jr. Spignesi	President And Ceo	Acquired A	12,787	$0.00	$0	12,787	Direct
29 May, 2026	Inese Lowenstein	Director	Acquired A	12,787	$0.00	$0	12,787	Direct
29 May, 2026	Inese Lowenstein	Director	Acquired A	12,787	$0.00	$0	12,787	Direct
29 May, 2026	Robert G. Jr. Spignesi	President And Ceo	Acquired A	12,787	$0.00	$0	12,787	Direct
29 May, 2026	Kirk Malloy	Director	Acquired A	12,787	$0.00	$0	12,787	Direct
29 May, 2026	Melinda Litherland Pei	Director	Acquired A	12,787	$0.00	$0	12,787	Direct
29 May, 2026	Sean M Wirtjes	Chief Financial Officer	Acquired A	12,787	$0.00	$0	12,787	Direct

Showing 1 to 20 of 262 transactions