SEC Form 4 · Updated Daily
BOLD
— BOUNDLESS BIO, INC. OwnershipInsider and institutional ownership derived from SEC Form 4 filings. Click any owner to see their holdings across every company they’ve filed on, and how their position has changed over time.
Current Reporting Owners
| Owner | Role | Shares Owned | As Of | Last Activity |
|---|---|---|---|---|
| TANG KEVIN | 10%+ Owner | 3,011,749 | 2026-10-26 | P |
| TANG CAPITAL MANAGEMENT LLC | 10%+ Owner | 3,011,749 | 2026-10-26 | P |
| RA CAPITAL MANAGEMENT, L.P. | 10%+ Owner · Director | 1,884,787 | 2024-04-02 | P |
| Kolchinsky Peter | 10%+ Owner · Director | 1,884,787 | 2024-04-02 | P |
| Shah Rajeev M. | 10%+ Owner · Director | 1,884,787 | 2024-04-02 | P |
| RA Capital Healthcare Fund LP | 10%+ Owner · Director | 1,884,787 | 2024-04-02 | P |
| RA Capital Nexus Fund II, L.P. | 10%+ Owner | 1,884,787 | 2024-04-02 | P |
| Wellington Biomedical Innovation Master Investors (Cayman) I L.P. | 10%+ Owner | 556,233 | 2024-04-02 | C |
| Lim Jonathan E | Director | 550,915 | 2024-04-02 | C |
| Hornby Zachary | Director · Officer | 256,410 | 2024-03-27 | — |
| Hassig Christian | Officer | 25,641 | 2024-03-27 | — |
| GILLIS STEVEN | 10%+ Owner | 16,000 | 2026-07-01 | M |
| NELSEN ROBERT | 10%+ Owner · Director | 16,000 | 2026-07-01 | M |
| Burow Kristina | 10%+ Owner · Director | 16,000 | 2026-07-01 | M |
| CRANDELL KEITH | 10%+ Owner | 16,000 | 2026-07-01 | M |
| ARCH Venture Fund X Overage, L.P. | 10%+ Owner | 16,000 | 2026-07-01 | M |
| ARCH Venture Partners X Overage, L.P. | 10%+ Owner | 16,000 | 2026-07-01 | M |
| ARCH Venture Partners X, LLC | 10%+ Owner | 16,000 | 2026-07-01 | M |
| BYBEE CLINTON | 10%+ Owner | 16,000 | 2026-07-01 | M |
| ARCH Venture Fund IX, L.P. | 10%+ Owner | 16,000 | 2026-07-01 | M |
| ARCH Venture Fund IX Overage, L.P. | 10%+ Owner | 16,000 | 2026-07-01 | M |
| ARCH Venture Partners IX, L.P. | 10%+ Owner | 16,000 | 2026-07-01 | M |
| ARCH Venture Partners IX Overage, L.P. | 10%+ Owner | 16,000 | 2026-07-01 | M |
| ARCH Venture Partners IX, LLC | 10%+ Owner | 16,000 | 2026-07-01 | M |
| HINKLE DAVID A | Officer | 100 | 2024-10-11 | — |
Recent Filings
| Date | Owner | Activity | Shares | Price | Owned After |
|---|---|---|---|---|---|
| 2026-10-26 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 9,606 | $2.38 | 3,011,749 |
| 2026-10-26 | TANG KEVIN | Open-market buy | 9,606 | $2.38 | 3,011,749 |
| 2026-10-23 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 6,234 | $2.38 | 3,002,143 |
| 2026-10-23 | TANG KEVIN | Open-market buy | 6,234 | $2.38 | 3,002,143 |
| 2026-10-22 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 5,800 | $2.40 | 2,995,909 |
| 2026-10-22 | TANG KEVIN | Open-market buy | 5,800 | $2.40 | 2,995,909 |
| 2026-10-20 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 220 | $2.37 | 2,990,109 |
| 2026-10-20 | TANG KEVIN | Open-market buy | 220 | $2.37 | 2,990,109 |
| 2026-10-19 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 18,279 | $2.33 | 2,989,889 |
| 2026-10-19 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 12,790 | $2.34 | 2,971,610 |
| 2026-10-19 | TANG KEVIN | Open-market buy | 18,279 | $2.33 | 2,989,889 |
| 2026-10-19 | TANG KEVIN | Open-market buy | 12,790 | $2.34 | 2,971,610 |
| 2026-10-16 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 118,185 | $2.34 | 2,958,820 |
| 2026-10-16 | TANG KEVIN | Open-market buy | 118,185 | $2.34 | 2,958,820 |
| 2026-08-26 | TANG CAPITAL MANAGEMENT LLC | Open-market sale | 18,300 | $2.97 | 2,840,635 |
| 2026-08-26 | TANG KEVIN | Open-market sale | 18,300 | $2.97 | 2,840,635 |
| 2026-07-21 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 2,975 | $2.44 | 2,858,935 |
| 2026-07-21 | TANG KEVIN | Open-market buy | 2,975 | $2.44 | 2,858,935 |
| 2026-07-20 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 1,623 | $2.44 | 2,855,960 |
| 2026-07-20 | TANG KEVIN | Open-market buy | 1,623 | $2.44 | 2,855,960 |
| 2026-07-17 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 265 | $2.44 | 2,854,337 |
| 2026-07-17 | TANG KEVIN | Open-market buy | 265 | $2.44 | 2,854,337 |
| 2026-07-16 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 18,491 | $2.44 | 2,854,072 |
| 2026-07-16 | TANG KEVIN | Open-market buy | 18,491 | $2.44 | 2,854,072 |
| 2026-07-15 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 1,600 | $2.44 | 2,835,581 |
| 2026-07-15 | TANG KEVIN | Open-market buy | 1,600 | $2.44 | 2,835,581 |
| 2026-07-14 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 43,878 | $2.43 | 2,833,981 |
| 2026-07-14 | TANG KEVIN | Open-market buy | 43,878 | $2.43 | 2,833,981 |
| 2026-07-13 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 48,211 | $2.42 | 2,790,103 |
| 2026-07-13 | TANG KEVIN | Open-market buy | 48,211 | $2.42 | 2,790,103 |
| 2026-07-10 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 43,367 | $2.43 | 2,741,892 |
| 2026-07-10 | TANG KEVIN | Open-market buy | 43,367 | $2.43 | 2,741,892 |
| 2026-07-09 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 7 | $2.48 | 2,698,525 |
| 2026-07-09 | TANG KEVIN | Open-market buy | 7 | $2.48 | 2,698,525 |
| 2026-07-08 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 14,338 | $2.46 | 2,698,518 |
| 2026-07-08 | TANG KEVIN | Open-market buy | 14,338 | $2.46 | 2,698,518 |
| 2026-07-07 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 15,810 | $2.48 | 2,684,180 |
| 2026-07-07 | TANG KEVIN | Open-market buy | 15,810 | $2.48 | 2,684,180 |
| 2026-07-06 | TANG CAPITAL MANAGEMENT LLC | Open-market buy | 27,062 | $2.49 | 2,668,370 |
| 2026-07-06 | TANG KEVIN | Open-market buy | 27,062 | $2.49 | 2,668,370 |
Source: SEC EDGAR Form 4 filings. For informational purposes only — not investment advice.