Rapid Micro Biosystems (RPID)
Rapid Micro Biosystems on one page: short interest, daily short volume, fails to deliver, planned sales, large holders, 13F holders, earnings dates and insider trades. Listed on Nasdaq, classified by the SEC as laboratory analytical instruments.
889K
Short interest
settlement 2026-10-15
3.8
Days to cover
+1.6 days vs prior
35.1%
Short share of volume
2026-11-02
2,187
Fails to deliver
settlement 2026-10-09
Fri 6 Nov
Next earnings
estimated date
$0
Insider flow, 90 days
0 buys, 0 sells
As of 2026-11-02.
Short interest
FINRA, twice a month. The newest 48 settlements in the table, 48 in the chart. JSONAs of 15 October 2026, short interest in RPID is 888,578 shares, down 51,798 shares over the last month. Over the last 48 readings it ranged from 31,130 shares (29 November 2024) to 1,605,753 shares (31 March 2025). At the reported average volume of 232K shares a day that is 3.8 days to cover.
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| Settlement | Shares short | Change | Avg daily volume | Days to cover |
|---|---|---|---|---|
| 2026-10-15 | 888,578 | +4.0% | 232,114 | 3.83 |
| 2026-09-30 | 853,972 | -9.2% | 374,932 | 2.28 |
| 2026-09-15 | 940,376 | +8.2% | 252,180 | 3.73 |
| 2026-08-31 | 869,421 | +3.0% | 194,265 | 4.48 |
| 2026-08-14 | 843,821 | +2.2% | 282,401 | 2.99 |
| 2026-07-31 | 825,765 | -2.0% | 163,470 | 5.05 |
| 2026-07-15 | 842,336 | +14.1% | 264,234 | 3.19 |
| 2026-06-30 | 738,469 | +20.3% | 199,837 | 3.70 |
| 2026-06-15 | 613,997 | -18.0% | 126,324 | 4.86 |
| 2026-05-29 | 748,445 | +13.4% | 191,578 | 3.91 |
| 2026-05-15 | 659,825 | -18.4% | 127,775 | 5.16 |
| 2026-04-30 | 808,896 | +48.7% | 193,334 | 4.18 |
| 2026-04-15 | 543,866 | +44.1% | 185,162 | 2.94 |
| 2026-03-31 | 377,502 | +18.9% | 276,966 | 1.36 |
| 2026-03-13 | 317,445 | +46.4% | 235,152 | 1.35 |
| 2026-02-27 | 216,880 | +22.1% | 100,609 | 2.16 |
| 2026-02-13 | 177,566 | +6.9% | 225,969 | 1.00 |
| 2026-01-30 | 166,073 | -7.0% | 426,155 | 1.00 |
| 2026-01-15 | 178,556 | -0.2% | 354,234 | 1.00 |
| 2025-12-31 | 178,907 | +10.9% | 146,428 | 1.22 |
| 2025-12-15 | 161,309 | -32.4% | 106,055 | 1.52 |
| 2025-11-28 | 238,781 | -20.8% | 101,544 | 2.35 |
| 2025-11-14 | 301,487 | -3.0% | 160,911 | 1.87 |
| 2025-10-31 | 310,680 | -3.7% | 82,097 | 3.78 |
| 2025-10-15 | 322,737 | -14.7% | 93,123 | 3.47 |
| 2025-09-30 | 378,496 | -1.6% | 60,001 | 6.31 |
| 2025-09-15 | 384,672 | +12.9% | 84,253 | 4.57 |
| 2025-08-29 | 340,630 | +0.7% | 59,738 | 5.70 |
| 2025-08-15 | 338,113 | -1.9% | 124,974 | 2.71 |
| 2025-07-31 | 344,774 | -15.8% | 111,443 | 3.09 |
| 2025-07-15 | 409,487 | -20.6% | 68,096 | 6.01 |
| 2025-06-30 | 515,575 | -25.1% | 86,705 | 5.95 |
| 2025-06-13 | 687,965 | -6.7% | 85,234 | 8.07 |
| 2025-05-30 | 737,522 | -25.1% | 97,175 | 7.59 |
| 2025-05-15 | 985,243 | -29.9% | 211,738 | 4.65 |
| 2025-04-30 | 1,406,279 | -2.6% | 98,404 | 14.29 |
| 2025-04-15 | 1,443,941 | -10.1% | 170,030 | 8.49 |
| 2025-03-31 | 1,605,753 | +35.6% | 190,667 | 8.42 |
| 2025-03-14 | 1,184,306 | +191.4% | 522,931 | 2.26 |
| 2025-02-28 | 406,473 | +202.3% | 1,461,392 | 1.00 |
| 2025-02-14 | 134,447 | +1.6% | 688,588 | 1.00 |
| 2025-01-31 | 132,346 | +16.5% | 291,884 | 1.00 |
| 2025-01-15 | 113,587 | +160.6% | 170,597 | 1.00 |
| 2024-12-31 | 43,583 | -25.1% | 72,704 | 1.00 |
| 2024-12-13 | 58,189 | +86.9% | 38,014 | 1.53 |
| 2024-11-29 | 31,130 | -29.3% | 65,318 | 1.00 |
| 2024-11-15 | 44,049 | -37.5% | 86,556 | 1.00 |
| 2024-10-31 | 70,423 | +299.6% | 133,966 | 1.00 |
Daily short volume
FINRA Reg SHO, the last 30 sessions. JSONAs of 2 November 2026, the short share of RPID volume is 35.1%, down 32.1 points over the last five sessions. Over the last 30 readings it ranged from 19.7% (7 October 2026) to 81.7% (12 October 2026). The latest reading is 13.8 points below the 30-session average of 48.9%, on 50K shares reported.
| Date | Short volume | Total volume | Short share | Exempt |
|---|---|---|---|---|
| 2026-11-02 | 17K | 50K | 35.1% | 236 |
| 2026-10-30 | 17K | 74K | 23.5% | 2 |
| 2026-10-29 | 46K | 89K | 51.4% | 0 |
| 2026-10-28 | 39K | 78K | 50.2% | 0 |
| 2026-10-27 | 13K | 45K | 28.6% | 0 |
| 2026-10-26 | 11K | 16K | 67.2% | 0 |
| 2026-10-23 | 16K | 23K | 72.9% | 0 |
| 2026-10-22 | 28K | 59K | 47.0% | 0 |
| 2026-10-21 | 20K | 35K | 59.0% | 0 |
| 2026-10-20 | 20K | 43K | 46.1% | 4,677 |
| 2026-10-19 | 46K | 82K | 56.5% | 25,904 |
| 2026-10-16 | 107K | 174K | 61.1% | 33,291 |
| 2026-10-15 | 24K | 33K | 72.5% | 0 |
| 2026-10-14 | 41K | 96K | 42.3% | 0 |
| 2026-10-13 | 61K | 122K | 50.4% | 0 |
| 2026-10-12 | 38K | 46K | 81.7% | 0 |
| 2026-10-09 | 65K | 144K | 45.2% | 0 |
| 2026-10-08 | 36K | 67K | 53.5% | 0 |
| 2026-10-07 | 28K | 144K | 19.7% | 0 |
| 2026-10-06 | 39K | 95K | 40.4% | 0 |
| 2026-10-05 | 173K | 276K | 62.5% | 2,102 |
| 2026-10-02 | 84K | 150K | 55.9% | 14,044 |
| 2026-10-01 | 170K | 317K | 53.4% | 2,210 |
| 2026-09-30 | 42K | 105K | 39.9% | 90 |
| 2026-09-29 | 81K | 137K | 59.1% | 3,977 |
| 2026-09-28 | 64K | 159K | 40.3% | 200 |
| 2026-09-25 | 48K | 99K | 48.5% | 0 |
| 2026-09-24 | 39K | 168K | 23.3% | 200 |
| 2026-09-23 | 47K | 103K | 45.3% | 0 |
| 2026-09-22 | 63K | 183K | 34.6% | 0 |
Fails to deliver
SEC, the last 30 settlement dates with a fail. JSONAs of 9 October 2026, the fails-to-deliver balance in RPID is 2,187 shares, up 2,125 shares over the last settlement date. Over the last 30 readings it ranged from 1 share (18 March 2026) to 61,313 shares (18 August 2026). The latest reading sits at the bottom of that range.
| Settlement | Shares failed | Price | Value |
|---|---|---|---|
| 2026-10-09 | 2,187 | $0.86 | $2K |
| 2026-10-06 | 62 | $0.98 | $61 |
| 2026-09-29 | 30 | $1.10 | $33 |
| 2026-09-22 | 483 | $1.13 | $546 |
| 2026-09-08 | 47,982 | $1.31 | $63K |
| 2026-09-03 | 5,448 | $1.39 | $8K |
| 2026-08-18 | 61,313 | $1.55 | $95K |
| 2026-08-10 | 14 | $1.73 | $24 |
| 2026-08-05 | 1,812 | $2.06 | $4K |
| 2026-08-03 | 1,337 | $2.13 | $3K |
| 2026-07-30 | 1,908 | $2.05 | $4K |
| 2026-07-28 | 1,005 | $2.01 | $2K |
| 2026-07-27 | 6,397 | $1.99 | $13K |
| 2026-07-24 | 4,705 | $1.99 | $9K |
| 2026-07-21 | 10,227 | $2.07 | $21K |
| 2026-07-15 | 12,349 | $2.07 | $26K |
| 2026-07-06 | 3,841 | $1.72 | $7K |
| 2026-07-02 | 265 | $1.71 | $453 |
| 2026-06-30 | 17 | $1.73 | $29 |
| 2026-06-25 | 1,482 | $1.68 | $2K |
| 2026-06-15 | 9 | $1.76 | $16 |
| 2026-05-19 | 9,050 | $1.96 | $18K |
| 2026-05-12 | 4,026 | $2.58 | $10K |
| 2026-05-06 | 3,090 | $2.48 | $8K |
| 2026-05-04 | 3 | $2.53 | $8 |
| 2026-04-24 | 250 | $2.25 | $563 |
| 2026-04-22 | 6,282 | $2.19 | $14K |
| 2026-03-18 | 1 | $2.92 | $3 |
| 2026-02-26 | 785 | $4.39 | $3K |
| 2026-01-23 | 376 | $4.41 | $2K |
Insider trades
SEC Form 4, newest first. JSONNo open-market insider trades were reported for RPID in the last 90 days. The most recent filings are listed below. Latest filing: Kollender Richard S (Director) on 2026-07-24.
| Date | Insider | Title | Type | Shares | Price | Value | Owned after |
|---|---|---|---|---|---|---|---|
| 2026-07-24 | Kollender Richard S | Director | Exercise or conversion | 2K | $0.75 | $1K | 134K |
| 2026-07-24 | Kollender Richard S | Director | Exercise or conversion | 2K | $0.75 | $1K | 132K |
| 2026-07-22 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Exercise or conversion | 1K | $0.75 | $1K | 1.2M |
| 2026-05-29 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Grant | 13K | $1.96 | $25K | 1.2M |
| 2026-05-29 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Grant | 13K | $1.96 | $25K | 569K |
| 2026-05-29 | PEI MELINDA LITHERLAND | Director | Grant | 13K | $1.96 | $25K | 101K |
| 2026-05-29 | Malloy Kirk | Director | Grant | 13K | $1.96 | $25K | 61K |
| 2026-05-29 | LOWENSTEIN INESE | Director | Grant | 13K | $1.96 | $25K | 71K |
| 2026-05-21 | PEI MELINDA LITHERLAND | Director | Grant | 19K | $0.00 | $0 | 88K |
| 2026-05-21 | Malloy Kirk | Director | Grant | 19K | $0.00 | $0 | 48K |
| 2026-05-21 | LOWENSTEIN INESE | Director | Grant | 19K | $0.00 | $0 | 58K |
| 2026-05-21 | Kollender Richard S | Director | Grant | 19K | $0.00 | $0 | 130K |
| 2026-05-21 | Bika Dafni | Director | Grant | 19K | $0.00 | $0 | 19K |
| 2026-03-11 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Sell | 10K | $4.32 | $41K | 317K |
| 2026-03-11 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Sell | 7K | $4.32 | $32K | 556K |
| 2026-03-10 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Sell | 18K | $4.11 | $74K | 1.2M |
| 2026-02-27 | RICCIARDI NATALE S | Director | Exercise or conversion | 842 | $0.75 | $632 | 29K |
| 2026-02-20 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Sell | 5K | $3.92 | $21K | 326K |
| 2026-02-20 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Sell | 17K | $3.92 | $68K | 564K |
| 2026-02-19 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Sell | 38K | $3.89 | $149K | 1.2M |
| 2026-02-11 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Grant | 74K | $0.00 | $0 | 332K |
| 2026-02-11 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Grant | 97K | $0.00 | $0 | 581K |
| 2026-02-11 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Grant | 264K | $0.00 | $0 | 1.2M |
| 2026-02-09 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Sell | 5K | $3.78 | $17K | 258K |
| 2026-02-09 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Sell | 13K | $3.78 | $49K | 962K |
| 2026-02-09 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Sell | 6K | $3.78 | $23K | 484K |
| 2026-02-04 | Longitude Venture Partners II, L.P. | TenPercentOwner | Sell | 49K | $3.88 | $190K | 0 |
| 2026-02-04 | Longitude Capital Partners II, LLC | 10% owner | Sell | 49K | $3.88 | $190K | 0 |
| 2026-02-03 | Longitude Prime Partners, LLC | TenPercentOwner | Sell | 28K | $4.24 | $117K | 49K |
| 2026-02-03 | Longitude Capital Partners II, LLC | 10% owner | Sell | 28K | $4.24 | $117K | 49K |
| 2026-02-02 | Longitude Prime Partners, LLC | TenPercentOwner | Sell | 28K | $4.25 | $117K | 77K |
| 2026-02-02 | Longitude Capital Partners II, LLC | 10% owner | Sell | 28K | $4.25 | $117K | 77K |
| 2026-01-30 | Longitude Prime Partners, LLC | TenPercentOwner | Sell | 46K | $4.54 | $209K | 104K |
| 2026-01-30 | Longitude Capital Partners II, LLC | 10% owner | Sell | 46K | $4.54 | $209K | 104K |
| 2026-01-23 | Longitude Prime Partners, LLC | TenPercentOwner | Sell | 8K | $4.06 | $31K | 4.0M |
| 2026-01-23 | Longitude Prime Partners, LLC | TenPercentOwner | Exercise (in or at the money) | 629K | $0.05 | $31K | 4.0M |
| 2026-01-23 | Longitude Capital Partners II, LLC | 10% owner | Sell | 8K | $4.06 | $31K | 4.0M |
| 2026-01-23 | Longitude Capital Partners II, LLC | 10% owner | Exercise (in or at the money) | 629K | $0.05 | $31K | 4.0M |
| 2025-11-14 | Malloy Kirk | Director | Gift | 40K | $0.00 | $0 | 29K |
| 2025-10-17 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Tax withholding | 5K | $3.08 | $15K | 975K |
| 2025-10-17 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Exercise or conversion | 8K | $0.75 | $6K | 980K |
| 2025-10-17 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Tax withholding | 2K | $3.08 | $6K | 972K |
| 2025-10-17 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Exercise or conversion | 3K | $0.75 | $3K | 974K |
| 2025-07-14 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Sell | 12K | $3.32 | $39K | 971K |
| 2025-07-14 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Exercise or conversion | 25K | $0.00 | $0 | 982K |
| 2025-07-11 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Sell | 12K | $3.33 | $39K | 957K |
| 2025-07-11 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Exercise or conversion | 25K | $0.00 | $0 | 969K |
| 2025-07-10 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Sell | 12K | $3.40 | $39K | 944K |
| 2025-07-10 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Exercise or conversion | 25K | $0.00 | $0 | 926K |
| 2025-07-09 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Sell | 11K | $3.51 | $39K | 901K |
| 2025-07-09 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Exercise or conversion | 25K | $0.00 | $0 | 912K |
| 2025-07-08 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Sell | 11K | $3.51 | $38K | 887K |
| 2025-07-08 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Exercise or conversion | 25K | $0.00 | $0 | 898K |
| 2025-05-22 | RICCIARDI NATALE S | Director | Grant | 14K | $0.00 | $0 | 29K |
| 2025-05-22 | Malloy Kirk | Director | Grant | 14K | $0.00 | $0 | 79K |
| 2025-05-22 | Kollender Richard S | Director | Grant | 14K | $0.00 | $0 | 111K |
| 2025-05-22 | PEI MELINDA LITHERLAND | Director | Grant | 14K | $0.00 | $0 | 69K |
| 2025-05-22 | LOWENSTEIN INESE | Director | Grant | 14K | $0.00 | $0 | 39K |
| 2025-03-09 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Tax withholding | 10K | $2.39 | $24K | 232K |
| 2025-03-09 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Tax withholding | 8K | $2.39 | $18K | 490K |
| 2025-03-09 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Tax withholding | 11K | $2.39 | $25K | 872K |
| 2025-02-18 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Grant | 365K | $0.00 | $0 | 883K |
| 2025-02-18 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Grant | 160K | $0.00 | $0 | 498K |
| 2025-02-18 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Grant | 44K | $0.00 | $0 | 242K |
| 2025-02-11 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Tax withholding | 11K | $2.68 | $29K | 516K |
| 2025-02-11 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Tax withholding | 5K | $2.68 | $12K | 338K |
| 2025-02-11 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Tax withholding | 7K | $2.68 | $19K | 198K |
| 2025-02-06 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Tax withholding | 13K | $3.10 | $40K | 527K |
| 2025-02-06 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Tax withholding | 6K | $3.10 | $18K | 342K |
| 2025-02-06 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Tax withholding | 5K | $3.10 | $14K | 205K |
| 2024-12-05 | PEI MELINDA LITHERLAND | Director | Buy | 9K | $1.04 | $9K | 54K |
| 2024-12-03 | PEI MELINDA LITHERLAND | Director | Buy | 11K | $1.00 | $11K | 45K |
| 2024-11-27 | PEI MELINDA LITHERLAND | Director | Buy | 20K | $1.05 | $21K | 34K |
| 2024-11-26 | PEI MELINDA LITHERLAND | Director | Buy | 108 | $1.04 | $112 | 14K |
| 2024-08-08 | Malloy Kirk | Director | Buy | 50K | $0.91 | $46K | 64K |
| 2024-08-07 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Buy | 10K | $0.78 | $8K | 348K |
| 2024-08-06 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Buy | 50K | $0.77 | $39K | 540K |
| 2024-08-06 | Kollender Richard S | Director | Buy | 65K | $0.77 | $50K | 97K |
| 2024-05-23 | Schwartz Jeffrey Lawrence | Director,TenPercentOwner | Grant | 14K | $0.00 | $0 | 14K |
| 2024-05-23 | Hirsch David | Director | Grant | 14K | $0.00 | $0 | 14K |
| 2024-05-23 | Malloy Kirk | Director | Grant | 14K | $0.00 | $0 | 14K |
| 2024-05-23 | Kollender Richard S | Director | Grant | 14K | $0.00 | $0 | 32K |
| 2024-05-23 | PEI MELINDA LITHERLAND | Director | Grant | 14K | $0.00 | $0 | 14K |
| 2024-05-23 | LOWENSTEIN INESE | Director | Grant | 14K | $0.00 | $0 | 24K |
| 2024-05-23 | RICCIARDI NATALE S | Director | Grant | 14K | $0.00 | $0 | 14K |
| 2024-03-11 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Tax withholding | 10K | $0.98 | $10K | 469K |
| 2024-03-11 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Tax withholding | 7K | $0.98 | $7K | 325K |
| 2024-03-11 | VEZINA VICTORIA | CHIEF HUMAN RESOURCES OFFICER | Tax withholding | 5K | $0.98 | $5K | 113K |
| 2024-03-11 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Tax withholding | 10K | $0.98 | $9K | 189K |
| 2024-02-12 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Tax withholding | 9K | $0.96 | $9K | 479K |
| 2024-02-12 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Tax withholding | 4K | $0.96 | $4K | 333K |
| 2024-02-12 | VEZINA VICTORIA | CHIEF HUMAN RESOURCES OFFICER | Tax withholding | 3K | $0.96 | $3K | 118K |
| 2024-02-12 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Tax withholding | 6K | $0.96 | $6K | 198K |
| 2024-02-06 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Grant | 113K | $0.00 | $0 | 489K |
| 2024-02-06 | VEZINA VICTORIA | CHIEF HUMAN RESOURCES OFFICER | Grant | 28K | $0.00 | $0 | 121K |
| 2024-02-06 | Wilson John J. Addington | CHIEF OPERATING OFFICER | Grant | 39K | $0.00 | $0 | 204K |
| 2024-02-06 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Grant | 51K | $0.00 | $0 | 337K |
| 2023-09-06 | WIRTJES SEAN M | CHIEF FINANCIAL OFFICER | Buy | 10K | $0.99 | $10K | 286K |
| 2023-08-15 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Buy | 20K | $0.97 | $19K | 376K |
| 2023-08-08 | Spignesi Robert G. Jr. | PRESIDENT AND CEO | Buy | 34K | $0.92 | $31K | 356K |
Form 4 filings are due within two business days of the trade. Insiders sell for many reasons that say nothing about the company; open-market buys are rarer.
Planned sales (Form 144)
Newest first. JSON13 Form 144 notices on file for RPID worth $518K at the prices reported; 0 in the last 90 days worth $0. Latest: Wilson John J. Addington filed on 2026-07-08 to sell 10,000 shares ($17K) from 2026-07-08.
| Filed | Seller | Shares | Market value | Of outstanding | Sale from | Broker |
|---|---|---|---|---|---|---|
| 2026-07-08 | Wilson John J. AddingtonFormer Officer | 10K | $17K | 0.024% | 2026-07-08 | Fidelity Brokerage Services LLC |
| 2026-07-01 | Wilson John J. AddingtonFormer Officer | 6K | $11K | 0.015% | 2026-07-01 | Fidelity Brokerage Services LLC |
| 2026-06-22 | Wilson John J. AddingtonFormer Officer | 4K | $6K | 0.009% | 2026-06-22 | Fidelity Brokerage Services LLC |
| 2026-06-10 | Wilson John J. AddingtonFormer Officer | 5K | $9K | 0.012% | 2026-06-10 | Fidelity Brokerage Services LLC |
| 2026-03-11 | WIRTJES SEAN MOfficer | 7K | $32K | 0.019% | 2026-03-11 | Fidelity Brokerage Services LLC |
| 2026-03-11 | Wilson John J. AddingtonOfficer | 10K | $41K | 0.024% | 2026-03-11 | Fidelity Brokerage Services LLC |
| 2026-03-10 | Spignesi Robert G. Jr.Officer, Director | 18K | $74K | 0.045% | 2026-03-10 | Fidelity Brokerage Services LLC |
| 2026-02-20 | Wilson John J. AddingtonOfficer | 5K | $21K | 0.014% | 2026-02-20 | Fidelity Brokerage Services LLC |
| 2026-02-20 | WIRTJES SEAN MOfficer | 17K | $68K | 0.043% | 2026-02-20 | Fidelity Brokerage Services LLC |
| 2026-02-19 | Spignesi Robert G. Jr.Officer, Director | 38K | $149K | 0.096% | 2026-02-19 | Fidelity Brokerage Services LLC |
| 2026-02-09 | WIRTJES SEAN MOfficer | 6K | $23K | 0.015% | 2026-02-09 | Fidelity Brokerage Services LLC |
| 2026-02-09 | Spignesi Robert G. Jr.Officer, Director | 13K | $49K | 0.032% | 2026-02-09 | Fidelity Brokerage Services LLC |
| 2026-02-09 | Wilson John J. AddingtonOfficer | 5K | $17K | 0.012% | 2026-02-09 | Fidelity Brokerage Services LLC |
Large holders (13D and 13G)
One row per reporting person with its latest filing, newest first. JSON10 holders report 5% or more of RPID in their latest filing, all on Schedule 13G (passive). The largest reported stake is Bain Capital Life Sciences Fund, L.P. at 16.8% of the class (7,651,369 shares), filed 2026-08-14 for an event on 2026-06-30.
| Filed | Form | Holder | Shares | Of class | Event |
|---|---|---|---|---|---|
| 2026-08-14 | 13G/Ano. 1 | Bain Capital Life Sciences Fund, L.P.partnership | 7.7M | 16.8% | 2026-06-30 |
| 2026-08-14 | 13G/Ano. 1 | BCIP Life Sciences Associates, LPpartnership | 783K | 1.7% | 2026-06-30 |
| 2026-08-14 | 13G | Armistice Capital, LLCinvestment adviser, other entity | 3.3M | 7.3% | 2026-06-30 |
| 2026-08-14 | 13G | Steven Boydparent holding company, individual | 3.3M | 7.3% | 2026-06-30 |
| 2026-05-15 | 13G/Ano. 2 | Longitude Capital Partners II, LLCother entity | 3.5M | 8.6% | 2026-03-31 |
| 2026-05-15 | 13G/Ano. 2 | Juliet Tammenoms Bakkerindividual | 3.5M | 8.6% | 2026-03-31 |
| 2026-05-15 | 13G/Ano. 2 | Patrick G. Enrightindividual | 3.5M | 8.6% | 2026-03-31 |
| 2026-05-15 | 13G/Ano. 2 | Longitude Venture Partners II, L.P.partnership | 3.5M | 8.6% | 2026-03-31 |
| 2026-05-15 | 13G/Ano. 2 | Longitude Prime Partners, LLCother entity | 0 | 0.0% | 2026-03-31 |
| 2026-05-15 | 13G/Ano. 2 | Longitude Prime Fund, L.P.partnership | 0 | 0.0% | 2026-03-31 |
| 2026-02-13 | 13G/Ano. 3 | Endeavour Medtech Growth II LPpartnership | 2.3M | 5.7% | 2025-12-31 |
| 2026-02-13 | 13G/Ano. 3 | Endeavour Medtech Growth II Parallel LPpartnership | 2.3M | 5.7% | 2025-12-31 |
| 2026-02-13 | 13G/Ano. 3 | Endeavour Medtech II GP Limitedpartnership | 2.3M | 5.7% | 2025-12-31 |
13F holders
Tracked managers holding RPID at their latest 13F. JSON3 of the 30 tracked managers held RPID at their latest 13F, $804K in total at quarter-end prices. Millennium Management is the largest at $409K (0.0% of its portfolio) as of 2026-06-30. Over the prior quarter 2 added shares and 1 cut.
| Fund | Quarter | Shares | Value | Of portfolio | Change in shares |
|---|---|---|---|---|---|
| Millennium Management | 2026-06-30 | 237K | $409K | 0.00% | -47K |
| Renaissance Technologies | 2026-06-30 | 212K | $367K | 0.00% | +85K |
| Citadel Advisors | 2026-06-30 | 16K | $28K | 0.00% | new |
Only the 30 tracked managers on the funds hub; a 13F reports long positions in US listed stock at quarter end, 45 days late, and says nothing about shorts or positions sold since.
What this page is
Rapid Micro Biosystems in the regulatory record
Regulators publish company data in separate files that never sit next to each other: FINRA's twice-monthly short interest, its daily short sale volume, the SEC's fails-to-deliver counts, and each insider's Form 4. A company page puts those series for one ticker on one URL, with planned sales, large holders, 13F holders and financials beside them, so the short position, the daily flow, the settlement fails and what insiders are doing can be read together.
Each section has its own history table, a one-line summary of the latest figures and its own JSON and CSV links, and says when its source last updated.
This page follows Rapid Micro Biosystems (RPID), SEC CIK 1380106, listed on Nasdaq, classified by the SEC as laboratory analytical instruments. The cross-market tables live on the short interest and insider transactions hubs.
Source and updates
- Short interest
- FINRA consolidated short interestSource: FINRA.Twice a month, about eight business days after settlement. Latest 2026-10-15.JSON and CSV
- Daily short volume
- FINRA Reg SHO daily filesSource: FINRA.Every trading day, the morning after FINRA posts it. Latest 2026-11-02.JSON and CSV
- Fails to deliver
- SEC fails-to-deliver dataSource: SEC.Twice a month, a few weeks after the half month ends. Latest 2026-10-09.JSON and CSV
- Planned sales
- SEC EDGAR Form 144Source: SEC.New notices appear shortly after the SEC posts them; a notice is filed on or before the sale. Latest 2026-07-08.JSON and CSV
- Large holders
- SEC EDGAR Schedule 13D and 13GSource: SEC.New filings appear shortly after the SEC posts them. A 13D is due within five business days of crossing 5%; a 13G follows the passive schedule. Latest 2026-08-14.JSON and CSV
- 13F holders
- SEC EDGAR Form 13F-HRSource: SEC.Quarterly, filed within 45 days of quarter end; 30 tracked managers. Latest 2026-06-30.JSON and CSV
- Earnings dates
- SEC EDGAR 8-K filings (Item 2.02)Source: SEC.Twice a day. Reported dates come from the company's 8-K filings; the next date is marked as an estimate until the 8-K arrives. Latest 2026-08-07.JSON and CSV
- Insider trades
- SEC EDGAR Form 4Source: SEC.New filings appear shortly after the SEC posts them; they're due two business days after the trade. Latest 2026-07-24.JSON and CSV
- Company record
- EDGAR filing index for CIK 1380106Ticker, name and exchange from the SEC's company list, refreshed weekly.
- Rate limits
- 10 requests a minute without a key, 30 with a free key from a free account.
How to read it
- Read the position against the flow: rising short interest with a high daily short share is new shorting; rising short interest with a normal short share is old shorts holding on.
- Insider buys next to a large short position are rare and stand out; insider sells next to one are common and mean little.
- Fails to deliver matter relative to the float, not in absolute shares; a million failed shares in a mega cap is noise.
Analysis of what the data shows, not advice. XOOMAR does not recommend buying, selling or holding anything.
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Datasets
Frequently Asked Questions
How much of RPID is sold short?
888,578 shares were held short at the 2026-10-15 settlement, 3.8 days of average volume. FINRA publishes the next count about eight business days after the 15th and the last business day of the month.
What is RPID's daily short volume?
On 2026-11-02, 17,454 of the 49,690 RPID shares reported to FINRA were sold short, 35.1% of the day's reported volume. Short volume is a flow for one day, not a position.
Does RPID have fails to deliver?
The SEC's latest file shows 2,187 RPID shares failed to deliver at settlement 2026-10-09. Fails are reported per settlement date and published twice a month with a lag.
Are RPID insiders buying or selling?
No open-market insider trades were reported for RPID in the last 90 days. The most recent filings are listed below. Latest filing: Kollender Richard S (Director) on 2026-07-24.
Have RPID insiders filed to sell?
13 Form 144 notices on file for RPID worth $518K at the prices reported; 0 in the last 90 days worth $0. Latest: Wilson John J. Addington filed on 2026-07-08 to sell 10,000 shares ($17K) from 2026-07-08.
Who owns 5% or more of RPID?
10 holders report 5% or more of RPID in their latest filing, all on Schedule 13G (passive). The largest reported stake is Bain Capital Life Sciences Fund, L.P. at 16.8% of the class (7,651,369 shares), filed 2026-08-14 for an event on 2026-06-30.
Which tracked 13F managers own RPID?
3 of the 30 tracked 13F managers held RPID shares at their latest filing, $804K in all. The largest: Izzy Englander's Millennium Management (237K shares, $409K), Renaissance Technologies (212K shares, $367K), Ken Griffin's Citadel Advisors (16K shares, $28K).
Data on this page is provided for informational purposes only and is not financial advice. See our editorial policy.