Boundless Bio, Inc.
BOLDFigures shown here come from public SEC filings. Dates beside each section show the available history.
How Boundless Bio, Inc. Makes Money
No flow chart is shown because the available revenue and expense lines do not reconcile exactly. The reported financial history below remains available.
Financial Summary
Choose a year or quarter, compare it with the same period a year earlier, and open any row for its full filing history.
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SEC filings supply these figures; updates after the dates shown are not included. This page includes 3 annual periods. The latest annual period ends Dec 31, 2025. The latest insider filing shown is dated Jun 29, 2026. The latest institutional report shown is dated Mar 31, 2026; other ownership filings may exist.
Ownership
Who holds the shares, as reported in SEC ownership filings.
Reported 13F positions
Each row shows what a filer reported for one date, not a current position. The link opens that filing.
| Filer | Report date | Shares | Value | Filing |
|---|---|---|---|---|
| WELLINGTON MANAGEMENT GROUP LLP | 2026-03-31 | 556,233 | Not shown | SEC filing |
| RBF Capital, LLC | 2026-03-31 | 200,000 | Not shown | SEC filing |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | 2026-03-31 | 50,500 | Not shown | SEC filing |
| CITIGROUP INC | 2026-03-31 | 8,837 | Not shown | SEC filing |
| Stonepine Capital Management, LLC | 2026-03-31 | 597,682 | Not shown | SEC filing |
| STATE STREET CORP | 2026-03-31 | 15,962 | Not shown | SEC filing |
| FMR LLC | 2026-03-31 | 2,695,455 | Not shown | SEC filing |
| GEODE CAPITAL MANAGEMENT, LLC | 2026-03-31 | 127,576 | Not shown | SEC filing |
| Optiver Holding B.V. | 2026-03-31 | 168 | Not shown | SEC filing |
| Sio Capital Management, LLC | 2026-03-31 | 163,679 | Not shown | SEC filing |
| Qube Research & Technologies Ltd | 2026-03-31 | 17,492 | Not shown | SEC filing |
| LANDSCAPE CAPITAL MANAGEMENT, L.L.C. | 2026-03-31 | 85,792 | Not shown | SEC filing |
| Pure Financial Advisors, LLC | 2026-03-31 | 10,100 | Not shown | SEC filing |
| BNP PARIBAS FINANCIAL MARKETS | 2026-03-31 | 178 | Not shown | SEC filing |
| CITADEL ADVISORS LLC | 2026-03-31 | 1,342,131 | Not shown | SEC filing |
| Walleye Capital LLC | 2026-03-31 | 39,624 | Not shown | SEC filing |
| Tower Research Capital LLC (TRC) | 2026-03-31 | 2,371 | Not shown | SEC filing |
| RENAISSANCE TECHNOLOGIES LLC | 2026-03-31 | 399,000 | Not shown | SEC filing |
| Squarepoint Ops LLC | 2026-03-31 | 16,374 | Not shown | SEC filing |
| MORGAN STANLEY | 2026-03-31 | 13,000 | Not shown | SEC filing |
- Each value is checked against Boundless Bio, Inc.'s share prices from within about three months of its report date (insiders' Form 4 trades and the latest close).
- Value not shown for 20 rows: the value per share could not be confirmed against the share prices on file from within three months of the report date.
Filer report history
Two reports per filer, as filed. No change is calculated, because the data on file cannot confirm that both reports describe the same security.
- Alyeska Investment Group, L.P.: 300,000 shares reported 2025-12-31; 300,000 shares reported 2026-03-31.
- XTX Topco Ltd: 39,577 shares reported 2025-12-31; 34,671 shares reported 2026-03-31.
- CWM, LLC: 9 shares reported 2025-12-31; 8 shares reported 2026-03-31.
- SECTORAL ASSET MANAGEMENT INC: 678,574 shares reported 2025-12-31; 678,574 shares reported 2026-03-31.
- Ensign Peak Advisors, Inc: 187,500 shares reported 2025-12-31; 187,500 shares reported 2026-03-31.
- BlackRock, Inc.: 67,048 shares reported 2025-12-31; 70,675 shares reported 2026-03-31.
- UBS Group AG: 23 shares reported 2025-12-31; 2 shares reported 2026-03-31.
- GSA CAPITAL PARTNERS LLP: 62,476 shares reported 2025-12-31; 96,824 shares reported 2026-03-31.
- ACADIAN ASSET MANAGEMENT LLC: 12,610 shares reported 2025-12-31; 12,610 shares reported 2026-03-31.
- JPMORGAN CHASE & CO: 169 shares reported 2025-12-31; 169 shares reported 2026-03-31.
- MILLENNIUM MANAGEMENT LLC: 135,410 shares reported 2025-12-31; 99,875 shares reported 2026-03-31.
- Squarepoint Ops LLC: 50,771 shares reported 2025-09-30; 16,374 shares reported 2026-03-31.
Showing the 12 most recent filer reports.
8 filers have only one report here.
Unusually large insider trades
Each trade is compared with the other insider trades of the same kind in the same security among Boundless Bio, Inc.'s recent filings on file. Size alone is context, not a prediction or evidence of improper trading.
- 2026-06-25 · TANG KEVIN: Larger than 12 of the 13 other insider purchases of Common Stock on file. SEC filing
- 2024-04-02 · RA Capital Healthcare Fund LP: Larger than all 13 other insider purchases of Common Stock on file. SEC filing
Independent insiders buying near the same time
- 2024-04-02–2024-04-02: 8 event(s) across 4 owner(s) — A cluster counts independent reporting owners that reported purchases within a set time. Co-filers and declared affiliates count once, and duplicate reports of the same event count once. ( filing , filing , filing , filing , filing , filing , filing , filing )
Purchases & sales (open market or private)
| Security | Code | Price | Filing | |||
|---|---|---|---|---|---|---|
| 2026-06-29 | TANG KEVIN · 10% owner | Common Stock | P — Open market or private purchase | +63,985 | 2.47 | SEC filing |
| 2026-06-29 | TANG KEVIN · 10% owner | Common Stock | P — Open market or private purchase | +777 | 2.48 | SEC filing |
| 2026-06-26 | TANG KEVIN · 10% owner | Common Stock | P — Open market or private purchase | +75,047 | 2.55 | SEC filing |
| 2026-06-26 | TANG KEVIN · 10% owner | Common Stock | P — Open market or private purchase | +134 | 2.54 | SEC filing |
| 2026-06-25 | TANG KEVIN · 10% owner | Common Stock | P — Open market or private purchase | +510 | 2.56 | SEC filing |
| 2026-06-25 | TANG KEVIN · 10% owner | Common Stock | P — Open market or private purchase | +145,880 | 2.48 | SEC filing |
| 2024-04-02 | CRANDELL KEITH · 10% owner | Common Stock | P — Open market or private purchase | +133,333 | 16.00 | SEC filing |
| 2024-04-02 | ARCH Venture Fund IX, L.P. · 10% owner | Common Stock | P — Open market or private purchase | +66,667 | 16.00 | SEC filing |
Showing 8 of 10 rows
Grants, exercises, tax & gifts
| Security | Code | Filing | |||
|---|---|---|---|---|---|
| 2026-06-15 | Christensen James · Director | Stock Option (right to buy) | A — Grant, award, or other acquisition | +32,000 | SEC filing |
| 2026-06-15 | Whiting Nancy · Director | Stock Option (right to buy) | A — Grant, award, or other acquisition | +32,000 | SEC filing |
| 2026-06-15 | Lew Jennifer · Director | Stock Option (right to buy) | A — Grant, award, or other acquisition | +32,000 | SEC filing |
| 2026-06-15 | Lim Jonathan E · Director | Stock Option (right to buy) | A — Grant, award, or other acquisition | +48,000 | SEC filing |
| 2026-01-23 | Hornby Zachary · President & CEO | Stock Option (right to buy) | A — Grant, award, or other acquisition | +600,000 | SEC filing |
| 2026-01-23 | Doebele Robert · Chief Medical Officer | Stock Option (right to buy) | A — Grant, award, or other acquisition | +230,000 | SEC filing |
| 2026-01-23 | Hassig Christian · Chief Scientific Officer | Stock Option (right to buy) | A — Grant, award, or other acquisition | +230,000 | SEC filing |
| 2026-01-23 | Oien Jessica · See Remarks | Stock Option (right to buy) | A — Grant, award, or other acquisition | +220,000 | SEC filing |
Showing 8 of 20 rows
Other activity
| Security | Code | Filing | |||
|---|---|---|---|---|---|
| 2024-08-19 | Hornby Zachary · President & CEO | Stock Option | D — Disposition to the issuer | −256,410 | SEC filing |
| 2024-08-19 | Wagner Klaus W. · Chief Medical Officer | Stock Option | D — Disposition to the issuer | −9,635 | SEC filing |
| 2024-08-19 | Abdollahian Neil · Chief Business Officer | Stock Option | D — Disposition to the issuer | −19,948 | SEC filing |
| 2024-08-19 | Oien Jessica · See Remarks | Stock Option | D — Disposition to the issuer | −42,051 | SEC filing |
| 2024-08-19 | Hornby Zachary · President & CEO | Stock Option | D — Disposition to the issuer | −471,282 | SEC filing |
| 2024-08-19 | Abdollahian Neil · Chief Business Officer | Stock Option | D — Disposition to the issuer | −54,871 | SEC filing |
| 2024-08-19 | Rubin Jami · Chief Financial Officer | Stock Option | D — Disposition to the issuer | −32,468 | SEC filing |
| 2024-08-19 | Abdollahian Neil · Chief Business Officer | Stock Option | D — Disposition to the issuer | −36,852 | SEC filing |
Showing 8 of 10 rows
These tables describe filed transactions, not current holdings. Prices are shown as filed; a currency is added only when the filing's data names one. Amended and possible duplicate rows are left out of size comparisons and transaction groups.