RAPID MICRO BIOSYSTEMS INC RPID
CLASS A COM · Common Stock · CUSIP 75340L104
- SectorTechnology
- IndustryLaboratory Analytical Instruments
- HeadquartersLexington, MA
- FilingsSEC EDGAR
34
institutional holders
-12 vs Q1 2026
17.5m
shares reported held*
$30.3mreported value*
5 new
9 added
13 reduced
16 sold out
net bought ≈ $2.9m (+1.7m shares)
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once. Holder counts are more reliable. Implied quarter-end price ≈ $1.73.
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 54 |
| Q4 2022 | 43 |
| Q1 2023 | 32 |
| Q2 2023 | 25 |
| Q3 2023 | 24 |
| Q4 2023 | 27 |
| Q1 2024 | 24 |
| Q2 2024 | 22 |
| Q3 2024 | 20 |
| Q4 2024 | 20 |
| Q1 2025 | 29 |
| Q2 2025 | 30 |
| Q3 2025 | 29 |
| Q4 2025 | 42 |
| Q1 2026 | 46 |
| Q2 2026 | 34 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Bought or addedCut or sold out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 4 | 10 |
| Q4 2024 | 8 | 4 |
| Q1 2025 | 21 | 8 |
| Q2 2025 | 14 | 10 |
| Q3 2025 | 13 | 11 |
| Q4 2025 | 25 | 10 |
| Q1 2026 | 27 | 17 |
| Q2 2026 | 14 | 29 |
Biggest buyers
| ARMISTICE CAPITAL, LLC | New | +3.3m |
| RENAISSANCE TECHNOLOGIES LLC | Added | +85.5k |
| Evernest Financial Advisors, LLC | Added | +73.5k |
| BlackRock, Inc. | Added | +32.6k |
| HRT FINANCIAL LP | New | +23.1k |
| XTX Topco Ltd | Added | +18.7k |
| DIMENSIONAL FUND ADVISORS LP | Added | +16.6k |
| CITADEL ADVISORS LLC | New | +16.1k |
| ALGERT GLOBAL LLC | Added | +15.1k |
| Larson Financial Group LLC | Added | +2.9k |
Biggest sellers
| ESSEX INVESTMENT MANAGEMENT CO LLC | Reduced | -521.2k |
| SEI INVESTMENTS CO | Reduced | -217.9k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Sold out | -212.1k |
| Advent International, L.P. | Reduced | -172.6k |
| Legato Capital Management LLC | Reduced | -155.4k |
| 683 Capital Management, LLC | Sold out | -120.8k |
| JANE STREET GROUP, LLC | Reduced | -107.0k |
| GOLDMAN SACHS GROUP INC | Sold out | -71.9k |
| FIFTH LANE CAPITAL, LP | Sold out | -71.0k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -46.7k |
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| Bain Capital Life Sciences Fund, L.P. 13G · exempt (held before listing) filed 2026-08-14 | 16.8% |
| Longitude Capital Partners II, LLC 13G · exempt (held before listing) filed 2026-05-15 | 8.6% |
| ARMISTICE CAPITAL, LLC 13G · institution new · filed 2026-08-14 | 7.3% |
Spignesi Robert G. Jr.
13D · may seek influence
new · filed 2025-08-19
Stated purposeThe information set forth or incorporated by reference in Items 3 and 6 of this Statement is incorporated by reference into this Item 4. The Reporting Person intends to continuously review his investment in the Issuer and may in the future determine (1) to acquire additional securities of the Issuer, through open market purchases, private agreements or otherwise, (2) to dispose of all or a portion of the securities of the Issuer owned by him or (3) to take any other available course of action. Notwithstanding anything contained herein, the Reporting Person specifically reserves the right to change his intention with respect to any or all of such matters. In reaching any decision as to his course of action (as well as to the specific elements thereof), the Reporting Person currently expect… Full filing |
6.3% |
| Endeavour Medtech Growth II LP 13G · passive investor filed 2026-02-13 | 5.7% |
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
BuyingSelling
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 1 | $41.4k | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
| Q2 2025 | 0 | — | 0 | — | — |
| Q3 2025 | 0 | — | 1 | $196.0k | — |
| Q4 2025 | 0 | — | 0 | — | — |
| Q1 2026 | 0 | — | 3 | $474.1k | — |
| Q2 2026 | 0 | — | 0 | — | — |
| Q3 2026 | 0 | — | 0 | — | — |
None reported since 1 Apr 2026.
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| Bain Capital Life Sciences Investors, LLC 0.87% of their portfolio | 8.4m $14.6m | Unchanged |
| ARMISTICE CAPITAL, LLC 0.16% of their portfolio | 3.3m $5.8m | New |
| ABG-WTT Global Life Science Capital Partners GP Ltd 37.39% of their portfolio | 1.8m $3.2m | Unchanged |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 982.0k $1.7m | Reduced -460 |
| Evernest Financial Advisors, LLC 0.18% of their portfolio | 506.0k $875.4k | Added +73.5k |
| Advent International, L.P. 0.00% of their portfolio | 379.8k $657.0k | Reduced -172.6k |
| ESSEX INVESTMENT MANAGEMENT CO LLC 0.08% of their portfolio | 362.7k $627.5k | Reduced -521.2k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 236.6k $409.3k | Reduced -46.7k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 228.0k $394.7k | Reduced -19.1k |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 212.1k $366.9k | Added +85.5k |
| BlackRock, Inc. 0.00% of their portfolio | 189.8k $328.4k | Added +32.6k |
| Legato Capital Management LLC 0.02% of their portfolio | 119.5k $206.8k | Reduced -155.4k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 110.5k $191.1k | Added +772 |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 104.2k $180.3k | Added +16.6k |
| STATE STREET CORP 0.00% of their portfolio | 93.9k $162.4k | Unchanged |
| XTX Topco Ltd 0.00% of their portfolio | 79.7k $137.9k | Added +18.7k |
| SEI INVESTMENTS CO 0.00% of their portfolio | 66.9k $115.7k | Reduced -217.9k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 42.1k $72.8k | Reduced -6.2k |
| ALGERT GLOBAL LLC 0.00% of their portfolio | 38.3k $66.3k | Added +15.1k |
| MORGAN STANLEY 0.00% of their portfolio | 27.6k $47.7k | Reduced -1.6k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 25.9k $44.9k | Reduced -107.0k |
| HRT FINANCIAL LP 0.00% of their portfolio | 23.1k $39.0k | New |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 16.1k $27.9k | New |
| OSAIC HOLDINGS, INC. 0.00% of their portfolio | 14.3k $24.7k | Added +300 |
| NANO CAP NEW MILLENNIUM GROWTH FUND L P 0.02% of their portfolio | 12.5k $21.6k | Unchanged |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 11.6k $20.1k | Reduced -5.3k |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 11.6k $20.1k | Unchanged |
| Larson Financial Group LLC 0.00% of their portfolio | 8.4k $14.5k | Added +2.9k |
| UBS Group AG 0.00% of their portfolio | 6.6k $11.4k | Reduced -4.6k |
| Tower Research Capital LLC (TRC) 0.00% of their portfolio | 1.9k $3.3k | New |
| BARCLAYS PLC 0.00% of their portfolio | 337 $583 | Reduced -21.3k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 109 $189 | Unchanged |
| Caitong International Asset Management Co., Ltd 0.00% of their portfolio | 35 $61 | New |
| SBI Securities Co., Ltd. 0.00% of their portfolio | 15 $26 | Unchanged |