Boundless Bio, Inc.
Ownership
Ownership Structure
Who owns Boundless Bio, Inc. (BOLD)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 70.7% of the shares are freely tradable; institutional investors hold 49.7%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| FMR Inc | 11.85 | 2,695,455 | +0.4 | 03/31/2026 |
| ARCH VENTURE CORP | 11.84 | 2,694,095 | +0.0 | 06/30/2026 |
| Stonepine Capital Management Llc | 2.63 | 597,682 | -15.8 | 03/31/2026 |
| Vanguard Capital Management, LLC | 2.63 | 597,192 | +0.0 | 03/31/2026 |
| Wellington Management Company LLP | 2.45 | 556,233 | +0.0 | 06/30/2026 |
| Millennium Management LLC | 2.10 | 478,639 | +379.2 | 06/30/2026 |
| Renaissance Technologies Corp | 1.75 | 399,000 | +16.9 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Fidelity Growth Compy Commingled Pl S | 5.46 | 1,243,083 | +0.0 | 07/31/2026 |
| Fidelity Growth Company Fund | 3.95 | 899,159 | +0.0 | 07/31/2026 |
| Vanguard MStar Total Stk Mkt Idx Invest | 1.96 | 445,181 | +0.0 | 07/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Tang Kevin | 10% Owner | 5,539,153 | 15,509,628 $ | Jul 8, 2026 | indirect |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Aug 26, 2026 | Tang Kevin | 10% Owner | Sell | 18,300 | 2.97 | 54,351 |
| Jul 21, 2026 | Tang Kevin | 10% Owner | Buy | 2,975 | 2.44 | 7,259 |
| Jul 20, 2026 | Tang Kevin | 10% Owner | Buy | 1,623 | 2.44 | 3,960 |
| Jul 17, 2026 | Tang Kevin | 10% Owner | Buy | 265 | 2.44 | 647 |
| Jul 16, 2026 | Tang Kevin | 10% Owner | Buy | 18,491 | 2.44 | 45,118 |
| Jul 15, 2026 | Tang Kevin | 10% Owner | Buy | 1,600 | 2.44 | 3,904 |
| Jul 14, 2026 | Tang Kevin | 10% Owner | Buy | 43,878 | 2.43 | 106,624 |
| Jul 13, 2026 | Tang Kevin | 10% Owner | Buy | 48,211 | 2.42 | 116,671 |
| Jul 10, 2026 | Tang Kevin | 10% Owner | Buy | 43,367 | 2.43 | 105,382 |
| Jul 9, 2026 | Tang Kevin | 10% Owner | Buy | 7 | 2.48 | 17 |
| Jul 8, 2026 | Tang Kevin | 10% Owner | Buy | 14,338 | 2.46 | 35,271 |
| Jul 7, 2026 | Tang Kevin | 10% Owner | Buy | 15,810 | 2.48 | 39,209 |
| Jul 6, 2026 | Tang Kevin | 10% Owner | Buy | 27,062 | 2.49 | 67,384 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 17, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.