Comparable stake leader
Longitude Capital Partners II, LLC
SEC ownership of RAPID MICRO BIOSYSTEMS, INC.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001380106.
Disclosed value leader
Bain Capital Life Sciences Investors, LLC
Comparable rows
50/50
Latest evidence
20 May 2026
- Symbol
- RPID on Nasdaq
- SEC evidence covered
- 3/4/5, 13D/G, and 13F
- Largest SEC-reported holder
- Longitude Capital Partners II, LLC
- Latest 13D/G holder
- Longitude Capital Partners II, LLC
- Latest parsed evidence date
- 20 May 2026
- CIK
- 0001380106
- Location
- Lexington, MA
Ownership snapshot
2 signals
Issuer
2 identity fields
Ownership snapshot
Top shareholders of RAPID MICRO BIOSYSTEMS, INC. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
Longitude Capital Partner...
Disclosed value leader
Bain Capital Life Science...
Comparable rows
50/50
Latest evidence
20 May 2026
3/4/5
13D/G
13F
Lead comparable stake: 8.6%
13D/G row: Longitude Capital Partners II, LLC
Showing 1-8 of 50 holder rows.
Quick read
Longitude Capital Partners II, LLC leads the comparable SEC ownership view at 8.6%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Comparable ownership
Top 5
Longitude Capital Partners II, LLC
8.6%
Robert G. Spignesi Jr.
6.3%
Endeavour Medtech Growth II LP
5.7%
Natale S. Ricciardi
0.07%
Bain Capital Life Sciences Invest...
21%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| Longitude Capital Partners II, LLC |
3/4/5
13D/G
10%+ Owner
|
8.6%
from 13D/G
|
$11,694,480
4,029,245 shares
|
-$663,949 | 04 Feb 2026 |
| Robert G. Spignesi Jr. |
13D/G
3/4/5
SPIGNESI ROBERT G JR · PRESIDENT AND CEO, Director
|
6.3%
|
$9,133,033
2,647,256 shares
|
$0 | 28 Mar 2024 |
| Endeavour Medtech Growth II LP |
13D/G
|
5.7%
|
$6,545,587
2,257,099 shares
|
$0 | 31 Dec 2025 |
| Natale S. Ricciardi |
3/4/5
Director
|
0.07%
|
$22,081
29,442 shares
|
— | 27 Feb 2026 |
| Bain Capital Life Sciences Investors, LLC |
3/4/5
13F
10%+ Owner · Company
|
21%
from 13F
|
$19,146,451
12,823,560 shares
mixed-class rows
|
— | 20 May 2026 |
| ABG-WTT Global Life Science Capital Partners GP Ltd |
13F
Company
|
4.5%
|
$4,195,632
1,848,296 shares
|
— | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
Company
|
2.4%
|
$2,230,261
982,494 shares
|
— | 31 Mar 2026 |
| ESSEX INVESTMENT MANAGEMENT CO LLC |
13F
Company
|
2.2%
|
$2,006,523
883,931 shares
|
— | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$1,333,959.
Buys
$0
Insiders: 0
Sells
$1,333,959
Insiders: 4
Net
-$1,333,959
Shares: -334,648
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 334,648
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 35,005 | $0 | $147,452 | -$147,452 |
| 3-6 | 0 | 242,200 | $0 | $990,551 | -$990,551 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 57,443 | $0 | $195,956 | -$195,956 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 24 reporting-owner rows connected to RAPID MICRO BIOSYSTEMS, INC.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
24
Largest Forms 3/4/5 holder
Bain Capital Life Sciences Fund, L.P.
Net 12M change
-$1,333,959
Latest report
21 May 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Bain Capital Life Sciences Fund, L.P. | 10%+ Owner | $19,146,451 | Median | 20 May 2026 | ||
| BCIP Life Sciences Associates, LP | 10%+ Owner | $19,146,451 | Median | 20 May 2026 | ||
| Bain Capital Life Sciences Partners, LP | 10%+ Owner | $19,146,451 | Median | 20 May 2026 | ||
| Bain Capital Life Sciences Investors, LLC | 10%+ Owner | $19,146,451 | Median | 20 May 2026 | ||
| KENNEDY LEWIS MANAGEMENT LP | 10%+ Owner | $13,548,284 | Filing P/S | 02 Jun 2022 | ||
| Longitude Capital Partners II, LLC | 10%+ Owner | $11,694,480 | -$663,949 | -5.4% | Mixed | 04 Feb 2026 |
| Jeffrey Lawrence Schwartz | Director, 10%+ Owner | $8,288,331 | Mixed | 23 May 2024 | ||
| Robert G. Spignesi Jr. | PRESIDENT AND CEO, Director | $4,809,830 | -$467,124 | -8.9% | Filing P/S | 10 Mar 2026 |
| Sean M. Wirtjes | Chief Financial Officer | $2,401,701 | -$122,785 | -4.9% | Filing P/S | 11 Mar 2026 |
| John J. Addington Wilson | Chief Operating Officer | $1,367,809 | -$80,101 | -5.5% | Filing P/S | 11 Mar 2026 |
| Richard S. Kollender | Director | $295,821 | Median | 21 May 2026 | ||
| Gurinder Grewal | 10%+ Owner | $291,863 | Mixed | 19 Jul 2021 | ||
| Melinda Litherland Pei | Director | $199,533 | Median | 21 May 2026 | ||
| Longitude Prime Partners, LLC | 10%+ Owner | $148,410 | Mixed | 19 Jul 2021 | ||
| Kirk Malloy | Director | $131,433 | Median | 21 May 2026 | ||
| Inese Lowenstein | Director | $131,433 | Median | 21 May 2026 | ||
| Jonathan Paris | Svp, General Counsel | $127,334 | Mixed | 09 Mar 2023 | ||
| Victoria Vezina | Chief Human Resources Officer | $110,468 | Mixed | 11 Mar 2024 | ||
| Dafni Bika | Director | $43,811 | Median | 21 May 2026 | ||
| Richard A. Keys | Chief Commercial Officer | $43,286 | Mixed | 11 Feb 2022 |
Recent insider transactions for RAPID MICRO BIOSYSTEMS, INC.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Kirk Malloy | RPID | Class A Common Stock | Award | 67.5% | 19,300 | 47,900 | 21 May 2026 | Direct | ||
| Kirk Malloy | RPID | Stock Option (Right to Buy) | Award | 38,700 | 38,700 | 21 May 2026 | Direct | |||
| Inese Lowenstein | RPID | Class A Common Stock | Award | 50% | 19,300 | 57,900 | 21 May 2026 | Direct | ||
| Inese Lowenstein | RPID | Stock Option (Right to Buy) | Award | 38,700 | 38,700 | 21 May 2026 | Direct | |||
| Melinda Litherland Pei | RPID | Class A Common Stock | Award | 28.1% | 19,300 | 87,900 | 21 May 2026 | Direct | ||
| Melinda Litherland Pei | RPID | Stock Option (Right to Buy) | Award | 38,700 | 38,700 | 21 May 2026 | Direct | |||
| Richard S. Kollender | RPID | Class A Common Stock | Award | 17.4% | 19,300 | 130,318 | 21 May 2026 | Direct | ||
| Richard S. Kollender | RPID | Stock Option (Right to Buy) | Award | 38,700 | 38,700 | 21 May 2026 | Direct | |||
| Dafni Bika | RPID | Class A Common Stock | Award | 19,300 | 19,300 | 21 May 2026 | Direct | |||
| Dafni Bika | RPID | Stock Option (Right to Buy) | Award | 38,700 | 38,700 | 21 May 2026 | Direct | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Series B Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Series B Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Series B Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Series B Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Series A Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Series A Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Series A Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Series A Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Pre-Funded Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Pre-Funded Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Pre-Funded Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| Bain Capital Life Sciences Investors, LLC | RPID | Pre-Funded Warrant (right to buy) | Purchase | 1,463,000 | 1,463,000 | 20 May 2026 | See footnotes | |||
| John J. Addington Wilson | RPID | Class A Common Stock | Sale | -2.94% | $41,467 | $4.32 | -9,603 | 316,762 | 11 Mar 2026 | Direct |
| Sean M. Wirtjes | RPID | Class A Common Stock | Sale | -1.33% | $32,299 | $4.32 | -7,480 | 556,194 | 11 Mar 2026 | Direct |
| Robert G. Spignesi Jr. | RPID | Class A Common Stock | Sale | -1.51% | $73,686 | $4.11 | -17,922 | 1,169,848 | 10 Mar 2026 | Direct |
| Natale S. Ricciardi | RPID | Class A Common Stock | Options Exercise | 2.94% | 842 | 29,442 | 27 Feb 2026 | Direct | ||
| Natale S. Ricciardi | RPID | Stock Option (Right to Buy) | Options Exercise | -100% | -842 | 0 | 27 Feb 2026 | Direct | ||
| John J. Addington Wilson | RPID | Class A Common Stock | Sale | -1.63% | $21,196 | $3.92 | -5,403 | 326,365 | 20 Feb 2026 | Direct |
| Sean M. Wirtjes | RPID | Class A Common Stock | Sale | -2.97% | $67,687 | $3.92 | -17,254 | 563,674 | 20 Feb 2026 | Direct |
| Robert G. Spignesi Jr. | RPID | Class A Common Stock | Sale | -3.13% | $148,912 | $3.89 | -38,327 | 1,187,770 | 19 Feb 2026 | Direct |
| John J. Addington Wilson | RPID | Class A Common Stock | Award | 28.7% | 74,000 | 331,768 | 11 Feb 2026 | Direct | ||
| John J. Addington Wilson | RPID | Stock Option (Right to Buy) | Award | 147,000 | 147,000 | 11 Feb 2026 | Direct | |||
| Sean M. Wirtjes | RPID | Class A Common Stock | Award | 20% | 97,000 | 580,928 | 11 Feb 2026 | Direct | ||
| Sean M. Wirtjes | RPID | Stock Option (Right to Buy) | Award | 193,000 | 193,000 | 11 Feb 2026 | Direct | |||
| Robert G. Spignesi Jr. | RPID | Class A Common Stock | Award | 27.4% | 264,000 | 1,226,097 | 11 Feb 2026 | Direct | ||
| Robert G. Spignesi Jr. | RPID | Stock Option (Right to Buy) | Award | 528,000 | 528,000 | 11 Feb 2026 | Direct | |||
| John J. Addington Wilson | RPID | Class A Common Stock | Sale | -1.76% | $17,438 | $3.78 | -4,610 | 257,768 | 09 Feb 2026 | Direct |
| Sean M. Wirtjes | RPID | Class A Common Stock | Sale | -1.23% | $22,798 | $3.78 | -6,027 | 483,928 | 09 Feb 2026 | Direct |
| Robert G. Spignesi Jr. | RPID | Class A Common Stock | Sale | -1.32% | $48,570 | $3.78 | -12,840 | 962,097 | 09 Feb 2026 | Direct |
| Longitude Capital Partners II, LLC | RPID | Class A Common Stock | Sale | -100% | $190,091 | $3.88 | -49,000 | 0 | 04 Feb 2026 | Held by Longitude Prime Fund, L.P. |
| Longitude Capital Partners II, LLC | RPID | Class A Common Stock | Sale | -36% | $116,641 | $4.24 | -27,500 | 49,000 | 03 Feb 2026 | Held by Longitude Prime Fund, L.P. |
| Longitude Capital Partners II, LLC | RPID | Class A Common Stock | Sale | -26.4% | $116,765 | $4.25 | -27,500 | 76,500 | 02 Feb 2026 | Held by Longitude Prime Fund, L.P. |
| Longitude Capital Partners II, LLC | RPID | Class A Common Stock | Sale | -30.7% | $209,001 | $4.54 | -46,000 | 104,000 | 30 Jan 2026 | Held by Longitude Prime Fund, L.P. |
| Longitude Capital Partners II, LLC | RPID | Class A Common Stock | Sale | -0.19% | $31,451 | $4.06 | -7,739 | 4,029,245 | 23 Jan 2026 | Held by Longitude Venture Partners II, L.P. |
| Longitude Capital Partners II, LLC | RPID | Class A Common Stock | Exercise of in-the-money or at-the-money derivative security | 18.5% | 629,032 | 4,036,984 | 23 Jan 2026 | Held by Longitude Venture Partners II, L.P. | ||
| Longitude Capital Partners II, LLC | RPID | Class A Common Stock | Exercise of in-the-money or at-the-money derivative security | -100% | -629,032 | 0 | 23 Jan 2026 | Held by Longitude Venture Partners II, L.P. | ||
| Kirk Malloy | RPID | Class A Common Stock | Gift | -58.3% | -40,000 | 28,600 | 14 Nov 2025 | Direct | ||
| Robert G. Spignesi Jr. | RPID | Class A Common Stock | Tax liability | -0.7% | -6,846 | 971,878 | 17 Oct 2025 | Direct | ||
| Robert G. Spignesi Jr. | RPID | Class A Common Stock | Options Exercise | 1.16% | 11,233 | 979,711 | 17 Oct 2025 | Direct | ||
| Robert G. Spignesi Jr. | RPID | Stock Option (Right to Buy) | Options Exercise | -100% | -11,233 | 0 | 17 Oct 2025 | Direct |
* marks a reported price that did not pass the local price check.