BOLD
Boundless Bio, Inc.
NASDAQ · Healthcare · Biotechnology · US
$2.48
−0.80%8
Insider buys (3m)
1
Insider sells (3m)
$372.6K
Net value (3m)
-0.4%
Price return (3m)
Form 4 filings
| Date | Insider | Activity | Shares | Price |
|---|---|---|---|---|
| Oct 29, 2026 | TANG KEVIN · 10 percent owner | Purchase | 10,707 | $2.40 |
| Oct 26, 2026 | TANG KEVIN · 10 percent owner | Purchase | 9,606 | $2.38 |
| Oct 26, 2026 | TANG KEVIN · 10 percent owner | Purchase | 5,800 | $2.40 |
| Oct 26, 2026 | TANG KEVIN · 10 percent owner | Purchase | 6,234 | $2.38 |
| Oct 20, 2026 | TANG KEVIN · 10 percent owner | Purchase | 12,790 | $2.34 |
| Oct 20, 2026 | TANG KEVIN · 10 percent owner | Purchase | 18,279 | $2.33 |
| Oct 20, 2026 | TANG KEVIN · 10 percent owner | Purchase | 220 | $2.37 |
| Oct 20, 2026 | TANG KEVIN · 10 percent owner | Purchase | 118,185 | $2.34 |
| Aug 28, 2026 | TANG KEVIN · 10 percent owner | Sale | 18,300 | $2.97 |
| Jul 21, 2026 | TANG KEVIN · 10 percent owner | Purchase | 1,623 | $2.44 |
| Jul 21, 2026 | TANG KEVIN · 10 percent owner | Purchase | 2,975 | $2.44 |
| Jul 21, 2026 | TANG KEVIN · 10 percent owner | Purchase | 265 | $2.44 |
| Jul 16, 2026 | TANG KEVIN · 10 percent owner | Purchase | 43,878 | $2.43 |
| Jul 16, 2026 | TANG KEVIN · 10 percent owner | Purchase | 1,600 | $2.44 |
| Jul 16, 2026 | TANG KEVIN · 10 percent owner | Purchase | 18,491 | $2.44 |
| Jul 13, 2026 | TANG KEVIN · 10 percent owner | Purchase | 7 | $2.48 |
| Jul 13, 2026 | TANG KEVIN · 10 percent owner | Purchase | 43,367 | $2.43 |
| Jul 13, 2026 | TANG KEVIN · 10 percent owner | Purchase | 48,211 | $2.42 |
| Jul 8, 2026 | TANG KEVIN · 10 percent owner | Purchase | 27,062 | $2.49 |
| Jul 8, 2026 | TANG KEVIN · 10 percent owner | Purchase | 14,338 | $2.46 |
| Jul 8, 2026 | TANG KEVIN · 10 percent owner | Purchase | 15,810 | $2.48 |
| Jul 6, 2026 | CRANDELL KEITH · 10 percent owner | M-Exempt | 16,000 | $1.03 |
| Jul 6, 2026 | CRANDELL KEITH · 10 percent owner | Sale | 16,000 | $2.49 |
| Jul 6, 2026 | ARCH Venture Fund IX, L.P. · 10 percent owner | M-Exempt | 16,000 | $1.03 |
| Jul 6, 2026 | ARCH Venture Fund IX, L.P. · 10 percent owner | Sale | 16,000 | $2.49 |
| Jul 2, 2026 | TANG KEVIN · 10 percent owner | Purchase | 25,930 | $2.54 |
| Jul 2, 2026 | TANG KEVIN · 10 percent owner | Purchase | 100 | $2.50 |
| Jul 2, 2026 | TANG KEVIN · 10 percent owner | Purchase | 71,612 | $2.49 |
| Jul 2, 2026 | TANG KEVIN · 10 percent owner | Purchase | 9,821 | $2.49 |
| Jun 29, 2026 | TANG KEVIN · 10 percent owner | Purchase | 134 | $2.54 |
Institutional positioning
13F filings over the trailing two quarters
New 18Increased 17Reduced 21Sold out 10
| Filer | Action | Shares | Filed |
|---|---|---|---|
| FMR LLC | Increased | 2,695,455 | May 15, 2026 |
| ARCH Venture Management, LLC | New Position | 2,694,095 | Aug 14, 2026 |
| FMR LLC | Reduced | 2,581,055 | Aug 13, 2026 |
| TANG CAPITAL MANAGEMENT LLC | New Position | 2,559,875 | Aug 14, 2026 |
| ADAR1 Capital Management, LLC | New Position | 1,968,216 | Aug 14, 2026 |
| CITADEL ADVISORS LLC | Reduced | 1,342,131 | May 15, 2026 |
| Cormorant Asset Management, LP | New Position | 1,000,000 | Aug 14, 2026 |
| SECTORAL ASSET MANAGEMENT INC | Unchanged | 678,574 | May 15, 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC | Increased | 614,923 | Aug 13, 2026 |
| STONEPINE CAPITAL MANAGEMENT, LLC | Reduced | 597,682 | May 14, 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC | New Position | 597,192 | May 15, 2026 |
| WELLINGTON MANAGEMENT GROUP LLP | Unchanged | 556,233 | Aug 14, 2026 |
| WELLINGTON MANAGEMENT GROUP LLP | Unchanged | 556,233 | May 15, 2026 |
| MILLENNIUM MANAGEMENT LLC | Increased | 478,639 | Aug 14, 2026 |
| RENAISSANCE TECHNOLOGIES LLC | Increased | 471,570 | Aug 13, 2026 |
Insider activity from SEC Form 4; institutional positioning from 13F filings · Latest filing Oct 29, 2026