As of September 29, 2026, Boundless Bio's top three insider holders are Kevin Tang (TenPercentOwner, 5.54Mn shares), Keith Crandell (TenPercentOwner, 1.18Mn shares), Kristina Burow (Director, 1.18Mn shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Kevin Tang | TenPercentOwner | 0 | 5,539,153 | 5,539,153 | 52.8% | 28 Aug, 2026 |
| 2 | Keith Crandell | TenPercentOwner | 0 | 1,181,766 | 1,181,766 | 11.3% | 04 Apr, 2024 |
| 3 | Kristina Burow | Director, TenPercentOwner | 0 | 1,181,766 | 1,181,766 | 11.3% | 04 Apr, 2024 |
| 4 | Venture Fund Ix, L.P. Arch | TenPercentOwner | 0 | 1,181,766 | 1,181,766 | 11.3% | 04 Apr, 2024 |
| 5 | Biomedical Innovation Master Investors (Cayman) I L.P. Wellington | TenPercentOwner | 556,233 | 0 | 556,233 | 5.3% | 02 Apr, 2024 |
| 6 | Jonathan E Lim | Director | 0 | 550,915 | 550,915 | 5.3% | 04 Apr, 2024 |
| 7 | Capital Management, L.P. Ra | TenPercentOwner | 0 | 295,844 | 295,844 | 2.8% | 04 Apr, 2024 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 26 Aug, 2026 | Kevin Tang | TenPercentOwner | Disposed S | 18,300 | $2.97 | $54.35K | 2,840,635 | Indirect |
| 17 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 265 | $2.44 | $647 | 2,854,337 | Indirect |
| 20 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 1,623 | $2.44 | $3.96K | 2,855,960 | Indirect |
| 21 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 2,975 | $2.44 | $7.26K | 2,858,935 | Indirect |
| 14 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 43,878 | $2.43 | $106.62K | 2,833,981 | Indirect |
| 15 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 1,600 | $2.44 | $3.90K | 2,835,581 | Indirect |
| 16 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 18,491 | $2.44 | $45.12K | 2,854,072 | Indirect |
| 09 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 7 | $2.48 | $17 | 2,698,525 | Indirect |
| 10 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 43,367 | $2.43 | $105.38K | 2,741,892 | Indirect |
| 13 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 48,211 | $2.42 | $116.67K | 2,790,103 | Indirect |
| 06 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 27,062 | $2.49 | $67.38K | 2,668,370 | Indirect |
| 07 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 15,810 | $2.48 | $39.21K | 2,684,180 | Indirect |
| 08 Jul, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 14,338 | $2.46 | $35.27K | 2,698,518 | Indirect |
| 01 Jul, 2026 | Keith Crandell | TenPercentOwner | Acquired M | 16,000 | $1.03 | $16.48K | 16,000 | Indirect |
| 01 Jul, 2026 | Venture Fund Ix, L.P. Arch | TenPercentOwner | Acquired M | 16,000 | $1.03 | $16.48K | 16,000 | Indirect |
| 01 Jul, 2026 | Venture Fund Ix, L.P. Arch | TenPercentOwner | Disposed S | 16,000 | $2.49 | $39.84K | 0 | Indirect |
| 01 Jul, 2026 | Keith Crandell | TenPercentOwner | Disposed S | 16,000 | $2.49 | $39.84K | 0 | Indirect |
| 01 Jul, 2026 | Venture Fund Ix, L.P. Arch | TenPercentOwner | Disposed M | 16,000 | $0.00 | $0 | 0 | Indirect |
| 01 Jul, 2026 | Keith Crandell | TenPercentOwner | Disposed M | 16,000 | $0.00 | $0 | 0 | Indirect |
| 30 Jun, 2026 | Kevin Tang | TenPercentOwner | Acquired P | 25,930 | $2.54 | $65.86K | 2,559,775 | Indirect |