BOLD · Insider trading · 13F holders · Congress trades
Boundless Bio, Inc. (BOLD)
Who is buying and selling BOLD: company insiders on SEC Form 4, hedge funds and superinvestors on Form 13F, and members of Congress under the STOCK Act. Every figure links to the filing or page it comes from.
- 13F filers holding
- 4
- Insider buys, 90 days
- $427K
- Insider sales, 90 days
- $54K
- Congress trades, 12 months
- 0
BOLD at a glance
- Between Aug 1, 2026 and Oct 29, 2026, 1 BOLD insider filed 3 open-market purchases worth $427K and 1 sale worth $54K on SEC Form 4.
- 4 13F filers hold BOLD among their 50 largest positions, worth $15.8M combined. The biggest bets by portfolio weight are ARCH Venture Management, LLC (0.6%), Tang Capital Management LLC (0.3%) and Cormorant Asset Management, LP (0.1%). In their latest 13Fs, 3 managers opened a new position and 0 added to one.
- No member of Congress has disclosed a trade in BOLD.
- BOLD last closed at $2.48 on Oct 29, 2026.
BOLD insider trading
Between Aug 1, 2026 and Oct 29, 2026, 1 BOLD insider filed 3 open-market purchases worth $427K and 1 sale worth $54K on SEC Form 4.
| Filed | Insider | Role | Trade | Shares | Price | Value | Form 4 |
|---|---|---|---|---|---|---|---|
| Oct 29, 2026 | Tang Kevin | 10% Owner | Buy | 10,707 | $2.40 | $26K | SEC |
| Oct 26, 2026 | Tang Kevin | 10% Owner | Buy | 21,640 | $2.39 | $52K | SEC |
| Oct 20, 2026 | Tang Kevin | 10% Owner | Buy | 149,474 | $2.34 | $350K | SEC |
| Aug 28, 2026 | Tang Kevin | 10% Owner | Sale | 18,300 | $2.97 | $54K | SEC |
Who owns BOLD? Hedge funds and superinvestors
4 13F filers hold BOLD among their 50 largest positions, worth $15.8M combined. The biggest bets by portfolio weight are ARCH Venture Management, LLC (0.6%), Tang Capital Management LLC (0.3%) and Cormorant Asset Management, LP (0.1%). In their latest 13Fs, 3 managers opened a new position and 0 added to one.
| Manager | % of portfolio | Value | Shares | Last quarter | 13F |
|---|---|---|---|---|---|
| ARCH Venture Management, LLCVenture capital | 0.6% | $6.7M | 2,694,095 | New | Q2 2026 |
| Tang Capital Management LLCHedge fund | 0.3% | $6.4M | 2,559,875 | — | Q2 2026 |
| Cormorant Asset Management, LPHedge fund | 0.1% | $2.5M | 1,000,000 | New | Q2 2026 |
| Superstring Capital Management LPHedge fund | 0.1% | $138K | 55,356 | New | Q2 2026 |
Each manager counts with its latest 13F (Q2 2026: 4). Screen BOLD in the grand portfolio →
BOLD stock trades by members of Congress
No member of Congress has disclosed a trade in BOLD.
Analysis mentioning BOLD
Posts from the blog that cover Boundless Bio, Inc., newest first.
BOLD questions and answers
Are insiders buying BOLD stock?
Between Aug 1, 2026 and Oct 29, 2026, 1 BOLD insider filed 3 open-market purchases worth $427K and 1 sale worth $54K on SEC Form 4.
Which hedge funds own BOLD?
4 13F filers hold BOLD among their 50 largest positions, worth $15.8M combined. The biggest bets by portfolio weight are ARCH Venture Management, LLC (0.6%), Tang Capital Management LLC (0.3%) and Cormorant Asset Management, LP (0.1%). In their latest 13Fs, 3 managers opened a new position and 0 added to one.
Has Congress traded BOLD?
No member of Congress has disclosed a trade in BOLD.
Who is the largest holder of BOLD?
Among 13F filers, ARCH Venture Management, LLC reports the largest BOLD position, $6.7M (2,694,095 shares) in its Q2 2026 13F. The biggest bet by portfolio weight is ARCH Venture Management, LLC's: 0.6% of its portfolio.
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