Boundless Bio, Inc. (BOLD) shareholders
BOLDNasdaqPharmaceutical PreparationsFiscal year ends December 31
$2.46+0.00 (0.00%)
Close on Nov 12, 2026Market cap $55.96MP/E –Yield –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
67.3%
15M of 23M shares
Institutional holders
40
13 new, 8 sold out
Net institutional buying
7M
In Q2 2026
Insider trades, 12 months
35 buys · 3 sales
Net bought $1.84M
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| Kristina Burow | 2,699,970 | – | 13D (active) | Apr 2, 2024 |
| FMR LLC Joint filing with Abigail P. Johnson (12.00%) | 2,684,022 | 12.00% | 13G (passive) amendment | Dec 31, 2025 |
| Kevin Tang Joint filing with Tang Capital Management, LLC (11.30%) | 2,533,845 | 11.30% | 13G (passive) | Jun 23, 2026 |
| Zachary Hornby | 2,426,857 | 9.80% | 13G (passive) | Oct 14, 2025 |
| ADAR1 Capital Management, LLC Joint filing with Daniel Schneeberger (8.80%) | 1,968,216 | 8.80% | 13G (passive) | Jun 30, 2026 |
| Bayer US Holding LP Joint filing with Bayer HealthCare LLC (7.30%), Bayer World Investments B.V. (7.30%) and 1 more | 1,615,201 | 7.30% | 13G (passive) | Apr 2, 2024 |
| Kenneth Griffin | 1,433,388 | 6.40% | 13G (passive) | Nov 26, 2025 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of BOLD | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| ARCH Venture Management, LLC | 2,694,095 | 11.84% | $6.74M | New | 0.61% |
| FMR LLC | 2,581,055 | 11.35% | $6.45M | −114,400 | 0.00% |
| Tang Capital Management LLC | 2,559,875 | 11.25% | $6.40M | New | 0.29% |
| ADAR1 Capital Management, LLC | 1,968,216 | 8.65% | $4.92M | New | 0.23% |
| Cormorant Asset Management, LP | 1,000,000 | 4.40% | $2.50M | New | 0.13% |
| Vanguard Capital Management LLC | 614,923 | 2.70% | $1.54M | +17,731 | 0.00% |
| Wellington Management Group Llp | 556,233 | 2.45% | $1.39M | – | 0.00% |
| Millennium Management LLC | 478,639 | 2.10% | $1.20M | +378,764 | 0.00% |
| Renaissance Technologies LLC | 471,570 | 2.07% | $1.18M | +72,570 | 0.00% |
| Alyeska Investment Group, L.P. | 300,000 | 1.32% | $750.00K | – | 0.00% |
| Affinity Asset Advisors, LLC | 250,000 | 1.10% | $625.00K | New | 0.03% |
| RBF Capital, LLC | 200,000 | 0.88% | $500.00K | – | 0.02% |
| Ensign Peak Advisors, Inc | 159,835 | 0.70% | $399.59K | −27,665 | 0.00% |
| Stonepine Capital Management, LLC | 154,595 | 0.68% | $386.49K | −443,087 | 0.22% |
| Acadian Asset Management LLC | 146,757 | 0.65% | $365.00K | +134,147 | 0.00% |
| Citadel Advisors LLC | 145,049 | 0.64% | $362.62K | −1,197,082 | 0.00% |
| Bridgeway Capital Management, LLC | 128,000 | 0.56% | $320.00K | +77,500 | 0.01% |
| Geode Capital Management, LLC | 116,736 | 0.51% | $291.84K | −10,840 | 0.00% |
| Hrt Financial LP | 116,288 | 0.51% | $290.00K | New | 0.00% |
| BlackRock, Inc. | 88,495 | 0.39% | $221.24K | +17,820 | 0.00% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 40 | 15M | 67.3% | 13 / 10 | 9 / 8 | 10M | 3M |
| Q1 2026 | 36 | 8M | 37.3% | 7 / 6 | 11 / 6 | 1M | 1M |
| Q4 2025 | 36 | 9M | 39.5% | 6 / 11 | 9 / 5 | 1M | 2M |
| Q3 2025 | 35 | 10M | 42.7% | 1 / 7 | 15 / 10 | 1M | 1M |
| Q2 2025 | 44 | 10M | 43.0% | 11 / 7 | 19 / 21 | 1M | 8M |
| Q1 2025 | 54 | 17M | 74.6% | 9 / 12 | 15 / 8 | 6M | 1M |
| Q4 2024 | 55 | 13M | 57.0% | 9 / 28 | 4 / 9 | 1M | 2M |
| Q3 2024 | 55 | 13M | 58.4% | 13 / 11 | 16 / 4 | 1M | 1M |
| Q2 2024 | 47 | 14M | 60.9% | 21 / 12 | 8 / 17 | 1M | 2M |
| Q1 2024 | 43 | 15M | 64.1% | 43 / 0 | 0 / 0 | 15M | 0M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
13 funds held BOLD in Q2 2026, 29% of their shares through ETFs. Each fund counts once per quarter, from its quarter-end report.
| Fund | Shares | % of BOLD | Value | % of fund | As of |
|---|---|---|---|---|---|
| Fidelity Growth Company Fund | 900,270 | 3.96% | $1.31M | 0.00% | May 31, 2026 |
| Vanguard Total Stock Market Index Fund | 445,181 | 1.96% | $1.11M | 0.00% | Jun 30, 2026 |
| Fidelity Growth Company K6 Fund | 226,498 | 1.00% | $328.42K | 0.00% | May 31, 2026 |
| Fidelity Series Growth Company Fund | 202,816 | 0.89% | $294.08K | 0.00% | May 31, 2026 |
| Vanguard Extended Market Index Fund | 152,011 | 0.67% | $380.03K | 0.00% | Jun 30, 2026 |
| Fidelity Extended Market Index Fund | 82,655 | 0.36% | $119.85K | 0.00% | May 31, 2026 |
| Ultra-Small Company Fund | 77,500 | 0.34% | $193.75K | 0.20% | Jun 30, 2026 |
| iShares Micro-Cap ETF | 58,851 | 0.26% | $147.13K | 0.01% | Jun 30, 2026 |
| Ultra-Small Company Market Fund | 50,500 | 0.22% | $126.25K | 0.09% | Jun 30, 2026 |
| Vanguard Balanced Index Fund | 17,731 | 0.08% | $44.33K | 0.00% | Jun 30, 2026 |
| Fidelity Series Total Market Index Fund | 15,411 | 0.07% | $22.35K | 0.00% | May 31, 2026 |
| Fidelity Total Market Index Fund | 8,946 | 0.04% | $12.97K | 0.00% | May 31, 2026 |
| 1290 VT Micro Cap Portfolio | 4,089 | 0.02% | $10.22K | 0.00% | Jun 30, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| Zachary Hornby | President & CEO, Director | 256,410 | 1.13% | Jan 26, 2026 |
| Jessica Oien | See Remarks | – | – | Jan 26, 2026 |
| Robert Doebele | Chief Medical Officer | – | – | Jan 26, 2026 |
| David A. Hinkle | See Remarks | 100 | 0.00% | Jan 26, 2026 |
| Christian Hassig | Chief Scientific Officer | 25,641 | 0.11% | Jan 26, 2026 |
| Jennifer Lew | Director | – | – | Jun 15, 2026 |
| Jonathan E. Lim | Director | 653,479 | 2.87% | Jun 15, 2026 |
| James Christensen | Director | – | – | Jun 15, 2026 |
| Nancy Whiting | Director | – | – | Jun 15, 2026 |
| Christine Brennan | Director | – | – | Jun 23, 2025 |
| Capital Management Llc Tang | 10% owner | 2,840,635 | 12.49% | Nov 10, 2026 |
| Kevin Tang | 10% owner | 3,035,567 | 13.34% | Nov 10, 2026 |
| Robert Nelsen | 10% owner | – | – | Jul 6, 2026 |
| Kristina Burow | 10% owner | 1,181,766 | 5.20% | Jul 6, 2026 |
| Clinton Bybee | 10% owner | – | – | Jul 6, 2026 |
| Keith Crandell | 10% owner | 27,349 | 0.12% | Jul 6, 2026 |
| Steven Gillis | 10% owner | 828,570 | 3.64% | Jul 6, 2026 |
| ARCH Venture Partners X, LLC | 10% owner | – | – | Jul 6, 2026 |
| ARCH Venture Partners X Overage, L.P. | 10% owner | – | – | Jul 6, 2026 |
| ARCH Venture Fund IX Overage, L.P. | 10% owner | – | – | Jul 6, 2026 |
| ARCH Venture Fund X Overage, L.P. | 10% owner | – | – | Jul 6, 2026 |
| ARCH Venture Partners IX Overage, L.P. | 10% owner | – | – | Jul 6, 2026 |
| ARCH Venture Partners IX, LLC | 10% owner | 617,092 | 2.71% | Jul 6, 2026 |
| ARCH Venture Fund IX, L.P. | 10% owner | – | – | Jul 6, 2026 |
| ARCH Venture Partners IX, L.P. | 10% owner | 683,759 | 3.01% | Jul 6, 2026 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| Kevin Tang 10% owner | Nov 10, 2026 | Buy | +249 | $2.40 | $598 | 3,035,567 |
| Kevin Tang 10% owner | Nov 6, 2026 | Buy | +1,700 | $2.40 | $4.08K | 3,035,318 |
| Kevin Tang 10% owner | Nov 5, 2026 | Buy | +8,390 | $2.40 | $20.14K | 3,033,618 |
| Kevin Tang 10% owner | Nov 4, 2026 | Buy | +517 | $2.40 | $1.24K | 3,025,228 |
| Kevin Tang 10% owner | Nov 3, 2026 | Buy | +2,255 | $2.40 | $5.41K | 3,024,711 |
| Kevin Tang 10% owner | Oct 27, 2026 | Buy | +10,707 | $2.40 | $25.70K | 3,022,456 |
| Kevin Tang 10% owner | Oct 26, 2026 | Buy | +9,606 | $2.38 | $22.86K | 3,011,749 |
| Kevin Tang 10% owner | Oct 23, 2026 | Buy | +6,234 | $2.38 | $14.84K | 3,002,143 |
| Kevin Tang 10% owner | Oct 22, 2026 | Buy | +5,800 | $2.40 | $13.92K | 2,995,909 |
| Kevin Tang 10% owner | Oct 20, 2026 | Buy | +220 | $2.37 | $521 | 2,990,109 |
| Kevin Tang 10% owner | Oct 19, 2026 | Buy | +18,279 | $2.33 | $42.59K | 2,989,889 |
| Kevin Tang 10% owner | Oct 19, 2026 | Buy | +12,790 | $2.34 | $29.93K | 2,971,610 |
| Kevin Tang 10% owner | Oct 16, 2026 | Buy | +118,185 | $2.34 | $276.55K | 2,958,820 |
| Capital Management Llc Tang 10% owner | Aug 26, 2026 | Sale | −18,300 | $2.97 | $54.35K | 2,840,635 |
| Kevin Tang 10% owner | Jul 21, 2026 | Buy | +2,975 | $2.44 | $7.26K | 2,858,935 |
| Kevin Tang 10% owner | Jul 20, 2026 | Buy | +1,623 | $2.44 | $3.96K | 2,855,960 |
| Kevin Tang 10% owner | Jul 17, 2026 | Buy | +265 | $2.44 | $647 | 2,854,337 |
| Kevin Tang 10% owner | Jul 16, 2026 | Buy | +18,491 | $2.44 | $45.12K | 2,854,072 |
| Kevin Tang 10% owner | Jul 15, 2026 | Buy | +1,600 | $2.44 | $3.90K | 2,835,581 |
| Kevin Tang 10% owner | Jul 14, 2026 | Buy | +43,878 | $2.43 | $106.62K | 2,833,981 |
| Kevin Tang 10% owner | Jul 13, 2026 | Buy | +48,211 | $2.42 | $116.67K | 2,790,103 |
| Kevin Tang 10% owner | Jul 10, 2026 | Buy | +43,367 | $2.43 | $105.38K | 2,741,892 |
| Kevin Tang 10% owner | Jul 9, 2026 | Buy | +7 | $2.48 | $17 | 2,698,525 |
| Kevin Tang 10% owner | Jul 8, 2026 | Buy | +14,338 | $2.46 | $35.27K | 2,698,518 |
| Kevin Tang 10% owner | Jul 7, 2026 | Buy | +15,810 | $2.48 | $39.21K | 2,684,180 |
| Kevin Tang 10% owner | Jul 6, 2026 | Buy | +27,062 | $2.49 | $67.38K | 2,668,370 |
| Kevin Tang 10% owner | Jul 2, 2026 | Buy | +9,821 | $2.49 | $24.45K | 2,641,308 |
| Steven Gillis 10% owner | Jul 1, 2026 | Sale | −16,000 | $2.49 | $39.84K | 0 |
| Steven Gillis 10% owner | Jul 1, 2026 | Option exercise | +16,000 | $1.03 | $16.48K | 16,000 |
| ARCH Venture Partners IX, L.P. 10% owner | Jul 1, 2026 | Sale | −16,000 | $2.49 | $39.84K | 0 |
| ARCH Venture Partners IX, L.P. 10% owner | Jul 1, 2026 | Option exercise | +16,000 | $1.03 | $16.48K | 16,000 |
| Kevin Tang 10% owner | Jul 1, 2026 | Buy | +71,612 | $2.49 | $178.31K | 2,631,487 |
| Kevin Tang 10% owner | Jun 30, 2026 | Buy | +100 | $2.50 | $250 | 2,559,875 |
| Kevin Tang 10% owner | Jun 30, 2026 | Buy | +25,930 | $2.54 | $65.86K | 2,559,775 |
| Kevin Tang 10% owner | Jun 29, 2026 | Buy | +63,985 | $2.47 | $158.04K | 2,533,068 |
| Kevin Tang 10% owner | Jun 29, 2026 | Buy | +777 | $2.48 | $1.93K | 2,533,845 |
| Kevin Tang 10% owner | Jun 26, 2026 | Buy | +134 | $2.54 | $340 | 2,469,083 |
| Kevin Tang 10% owner | Jun 26, 2026 | Buy | +75,047 | $2.55 | $191.37K | 2,468,949 |
| Kevin Tang 10% owner | Jun 25, 2026 | Buy | +145,880 | $2.48 | $361.78K | 2,393,392 |
| Kevin Tang 10% owner | Jun 25, 2026 | Buy | +510 | $2.56 | $1.31K | 2,393,902 |
| Jonathan E. Lim Director | Apr 2, 2024 | Conversion | +525,274 | – | – | 550,915 |
| ARCH Venture Partners IX, LLC 10% owner | Apr 2, 2024 | Conversion | +589,743 | – | – | 617,092 |
| ARCH Venture Partners IX, LLC 10% owner | Apr 2, 2024 | Buy | +133,333 | $16.00 | $2.13M | 1,181,766 |
| ARCH Venture Partners IX, LLC 10% owner | Apr 2, 2024 | Conversion | +787,545 | – | – | 828,570 |
| ARCH Venture Partners IX, LLC 10% owner | Apr 2, 2024 | Conversion | +1,048,433 | – | – | 1,048,433 |
| ARCH Venture Partners IX, LLC 10% owner | Apr 2, 2024 | Buy | +66,667 | $16.00 | $1.07M | 683,759 |
| Steven Gillis 10% owner | Apr 2, 2024 | Buy | +66,667 | $16.00 | $1.07M | 683,759 |
| Steven Gillis 10% owner | Apr 2, 2024 | Conversion | +1,048,433 | – | – | 1,048,433 |
| Steven Gillis 10% owner | Apr 2, 2024 | Conversion | +787,545 | – | – | 828,570 |
| Steven Gillis 10% owner | Apr 2, 2024 | Conversion | +589,743 | – | – | 617,092 |
| Steven Gillis 10% owner | Apr 2, 2024 | Buy | +133,333 | $16.00 | $2.13M | 1,181,766 |
| Kristina Burow Director, 10% owner | Apr 2, 2024 | Buy | +133,333 | $16.00 | $2.13M | 1,181,766 |
| Kristina Burow Director, 10% owner | Apr 2, 2024 | Conversion | +589,743 | – | – | 617,092 |
| Kristina Burow Director, 10% owner | Apr 2, 2024 | Conversion | +787,545 | – | – | 828,570 |
| Kristina Burow Director, 10% owner | Apr 2, 2024 | Buy | +66,667 | $16.00 | $1.07M | 683,759 |
| Kristina Burow Director, 10% owner | Apr 2, 2024 | Conversion | +1,048,433 | – | – | 1,048,433 |
| Peter Kolchinsky 10% owner | Apr 2, 2024 | Buy | +296,875 | $16.00 | $4.75M | 1,884,787 |
| Peter Kolchinsky 10% owner | Apr 2, 2024 | Conversion | +280,219 | – | – | 280,219 |
| Peter Kolchinsky 10% owner | Apr 2, 2024 | Buy | +15,625 | $16.00 | $250.00K | 295,844 |
| Peter Kolchinsky 10% owner | Apr 2, 2024 | Conversion | +1,587,912 | – | – | 1,587,912 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Short interest
Shares sold short and not yet bought back, as of Oct 30, 2026 (FINRA, reported twice a month)
Short % of float
5.49%
1M shares short
Days to cover
5.1
At 0M shares a day
Change since last report
+0.2%
From 1M shares
Short volume, 20 days
29.6%
Of volume reported to FINRA
Shares sold short, last 12 months
Short sale volume counts trades marked short on any given day, including market-maker hedging, so it runs far higher than the share of Boundless Bio's stock actually held short. Settlement fails (shares not delivered on time) peaked at 5,254 shares on Oct 8, 2026 over the last 90 days.
See a number that looks wrong?