Boundless Bio, Inc. (BOLD) Ownership
BOLD ownership summary
as of October 18, 2026- Institutions
- 67.3% of shares outstanding
- Insiders
- 12.53% of shares outstanding
- Shares outstanding
- 23.1M
- Float
- 15.8M shares available to trade
- Short interest
- 5.52% 778K shares short
- Days to cover
- 5.97 short interest down 4.1% vs prior month
- Institutions 67.26%
- Insiders 12.53%
- Other investors 20.21%
BOLD top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | ARCH VENTURE CORP | 11.66% | 2.7M | $6.3M | +2.7M (0.0%) | June 30, 2026 |
| 2 | FMR Inc | 11.17% | 2.6M | $6.0M | −114,400 (−4.2%) | June 30, 2026 |
| 3 | TANG CAPITAL MANAGEMENT LLC | 11.08% | 2.6M | $6.0M | +2.6M (0.0%) | June 30, 2026 |
| 4 | ADAR1 Capital Management LLC | 8.52% | 2.0M | $4.6M | +2.0M (0.0%) | June 30, 2026 |
| 5 | Cormorant Asset Management, LLC | 4.33% | 1.0M | $2.3M | +1.0M (0.0%) | June 30, 2026 |
| 6 | Vanguard Capital Management, LLC | 2.66% | 615K | $1.4M | +17,731 (+3.0%) | June 30, 2026 |
| 7 | Wellington Management Company LLP | 2.41% | 556K | $1.3M | — | June 30, 2026 |
| 8 | Millennium Management LLC | 2.07% | 479K | $1.1M | +378,764 (+379.2%) | June 30, 2026 |
| 9 | Renaissance Technologies Corp | 2.04% | 472K | $1.1M | +72,570 (+18.2%) | June 30, 2026 |
| 10 | Alyeska Investment Group, L.P. | 1.30% | 300K | $702,000 | — | June 30, 2026 |
| 11 | Affinity Asset Advisors, LLC | 1.08% | 250K | $585,000 | +250,000 (0.0%) | June 30, 2026 |
| 12 | RBF LLC | 0.87% | 200K | $468,000 | — | June 30, 2026 |
| 13 | Ensign Peak Advisors Inc | 0.69% | 160K | $374,014 | −27,665 (−14.8%) | June 30, 2026 |
| 14 | Stonepine Capital Management Llc | 0.67% | 155K | $361,752 | −443,087 (−74.1%) | June 30, 2026 |
| 15 | Acadian Asset Management LLC | 0.64% | 147K | $343,411 | +134,147 (+1,063.8%) | June 30, 2026 |
| 16 | Citadel Advisors Llc | 0.63% | 145K | $339,415 | −1.2M (−89.2%) | June 30, 2026 |
| 17 | Bridgeway Capital Management, LLC | 0.55% | 128K | $299,520 | +77,500 (+153.5%) | June 30, 2026 |
| 18 | Geode Capital Management, LLC | 0.51% | 117K | $273,162 | −10,840 (−8.5%) | June 30, 2026 |
| 19 | HRT FINANCIAL LLC | 0.50% | 116K | $272,114 | +116,288 (0.0%) | June 30, 2026 |
| 20 | BlackRock Inc | 0.38% | 88K | $207,078 | +17,820 (+25.2%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 12 holders added 9.3M shares and 5 cut 1.8M.
BOLD top mutual fund and ETF holders
13 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Fidelity Growth Company Fund | 3.89% | 899K | $2.1M | — | August 31, 2026 |
| 2 | Vanguard MStar Total Stk Mkt Idx Invest | 1.93% | 445K | $1.0M | — | August 31, 2026 |
| 3 | Fidelity Growth Company K6 | 0.98% | 228K | $532,605 | — | August 31, 2026 |
| 4 | Fidelity Series Growth Company | 0.84% | 193K | $451,891 | −6,600 (−3.3%) | August 31, 2026 |
| 5 | Bridgeway Ultra-Small Company | 0.34% | 78K | $181,350 | +77,500 (0.0%) | June 30, 2026 |
| 6 | Fidelity Extended Market Index | 0.29% | 68K | $158,273 | −363 (−0.5%) | August 31, 2026 |
| 7 | iShares Micro-Cap ETF | 0.24% | 56K | $131,372 | −387 (−0.7%) | September 30, 2026 |
| 8 | Fidelity Series Total Market Index | 0.08% | 19K | $44,411 | — | August 31, 2026 |
| 9 | Vanguard Balanced Index Inv | 0.08% | 18K | $41,491 | — | August 31, 2026 |
| 10 | China Universal Gbl YLBJ QDII CNH | 0.07% | 17K | $39,546 | +16,900 (0.0%) | June 30, 2026 |
| 11 | Fidelity Total Market Index | 0.04% | 8,946 | $20,934 | — | August 31, 2026 |
| 12 | 1290 VT Micro Cap K | 0.02% | 4,089 | $9,568 | — | August 31, 2026 |
| 13 | JHVIT Total Stock Market Index I | <0.01% | 883 | $2,066 | +883 (0.0%) | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
BOLD insider transactions
latest 2| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2024-04-02 | Kristina Burow | Buy | $16.00 | 200,000 | $3.2M |
| 2024-04-02 | Ra Capital Management, L.P. | Buy | $16.00 | 312,500 | $5.0M |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
BOLD shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns BOLD
Institutional investors own 67.3% of Boundless Bio's shares and insiders 12.53%. The largest holder is ARCH VENTURE CORP with 11.66% of the shares (2.7M), as of June 30, 2026. Among the top 20 institutions, 12 added shares and 5 reduced their stake in the latest filings. Short interest is 5.52% of the float, or 5.97 days of average trading volume. The share count rose 109.5% since 2016.
Related: BOLD analyst forecast, BOLD key metrics. See the BOLD stock overview for the latest quote and news.
BOLD ownership FAQ
Who owns the most Boundless Bio stock?
The largest shareholders of Boundless Bio are ARCH VENTURE CORP (11.66%), FMR Inc (11.17%), TANG CAPITAL MANAGEMENT LLC (11.08%), ADAR1 Capital Management LLC (8.52%), Cormorant Asset Management, LLC (4.33%).
What percentage of Boundless Bio is owned by institutions?
Institutions hold 67.3% of Boundless Bio's shares outstanding; insiders hold 12.53%.
Which funds own Boundless Bio?
The largest fund holders of Boundless Bio are Fidelity Growth Company Fund (3.89%), Vanguard MStar Total Stk Mkt Idx Invest (1.93%), Fidelity Growth Company K6 (0.98%), Fidelity Series Growth Company (0.84%), Bridgeway Ultra-Small Company (0.34%).
What is Boundless Bio's short interest?
778K shares of Boundless Bio were sold short, 5.52% of the float; at the average daily volume it would take 5.97 days to cover.
Are insiders buying or selling Boundless Bio?
Of the latest 2 reported insider transactions in Boundless Bio (since April 2, 2024), 2 were purchases and 0 were sales.
How many shares of Boundless Bio are outstanding?
Boundless Bio has 23.1M shares outstanding, of which 15.8M are in the public float.