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Boundless Bio, Inc. (BOLD)
United States · Delayed Price · Currency is USD
Pharmaceutical Preparations
2.38+0.02 (+0.85%)
Insider Score
––Not scored
BOLD Insider Score
Insiders filed in the last 90 days, but none of those trades qualified for scoring — round-trip buys and filings whose price is far off the market are excluded.
BOLD Stock Insider Trading Activity
BOLD stock’s insider trading shows 26 purchases for an estimated $1.86M and 3 sales on the open market for an estimated $134.03K by company insiders over the last 6 months.
Not enough price history.
Insider Trading Activity (Form 4 Filings)
An insider trade occurs when an individual that has non-public information about a company buys or sells shares of that company’s stock. Examples of insiders include a company’s executive officers (CEO, CFO, COO), its board of directors, and its major shareholders. Insiders are required to submit their trading activity to the SEC through Form 4 filings.
Scored window · last 90 days0 qualifying buys0 insiders$349.59K bought— these are the numbers in the rankings table; the full history below shows every filing (buys, sells and older activity).
| Insider | Action | Shares | Avg Cost | Total | Δ Holdings | Held After | Date | Grade | Form 4 |
|---|---|---|---|---|---|---|---|---|---|
| TANG KEVIN Other | Buy | 220 | $2.37 | $521.4 | 0.0% | 2,990,109 | Oct 20, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 18,279 | $2.33 | $42.59K | 0.6% | 2,989,889 | Oct 19, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 12,790 | $2.34 | $29.93K | 0.4% | 2,971,610 | Oct 19, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 118,185 | $2.34 | $276.55K | 4.2% | 2,958,820 | Oct 16, 2026 | — | Form 4 |
| TANG KEVIN Other | Sell | 18,300 | $2.97 | $54.35K | 0.6% | 2,840,635 | Aug 26, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 2,975 | $2.44 | $7.26K | 0.1% | 2,858,935 | Jul 21, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 1,623 | $2.44 | $3.96K | 0.1% | 2,855,960 | Jul 20, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 265 | $2.44 | $646.6 | 0.0% | 2,854,337 | Jul 17, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 18,491 | $2.44 | $45.12K | 0.7% | 2,854,072 | Jul 16, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 1,600 | $2.44 | $3.90K | 0.1% | 2,835,581 | Jul 15, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 43,878 | $2.43 | $106.62K | 1.6% | 2,833,981 | Jul 14, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 48,211 | $2.42 | $116.67K | 1.8% | 2,790,103 | Jul 13, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 43,367 | $2.43 | $105.38K | 1.6% | 2,741,892 | Jul 10, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 7 | $2.48 | $17.36 | 0.0% | 2,698,525 | Jul 9, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 14,338 | $2.46 | $35.27K | 0.5% | 2,698,518 | Jul 8, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 15,810 | $2.48 | $39.21K | 0.6% | 2,684,180 | Jul 7, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 27,062 | $2.49 | $67.38K | 1.0% | 2,668,370 | Jul 6, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 9,821 | $2.49 | $24.45K | 0.4% | 2,641,308 | Jul 2, 2026 | — | Form 4 |
| ARCH Venture Fund IX, L.P. Other | Option exercise | 16,000 | $1.03 | $16.48K | New | 16,000 | Jul 1, 2026 | — | Form 4 |
| ARCH Venture Fund IX, L.P. Other | Sell | 16,000 | $2.49 | $39.84K | 100% | 0 | Jul 1, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 71,612 | $2.49 | $178.31K | 2.8% | 2,631,487 | Jul 1, 2026 | — | Form 4 |
| CRANDELL KEITH Other | Option exercise | 16,000 | $1.03 | $16.48K | New | 16,000 | Jul 1, 2026 | — | Form 4 |
| CRANDELL KEITH Other | Sell | 16,000 | $2.49 | $39.84K | 100% | 0 | Jul 1, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 25,930 | $2.54 | $65.86K | 1.0% | 2,559,775 | Jun 30, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 100 | $2.50 | $250 | 0.0% | 2,559,875 | Jun 30, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 63,985 | $2.47 | $158.04K | 2.6% | 2,533,068 | Jun 29, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 777 | $2.48 | $1.93K | 0.0% | 2,533,845 | Jun 29, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 134 | $2.54 | $340.36 | 0.0% | 2,469,083 | Jun 26, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 75,047 | $2.55 | $191.37K | 3.1% | 2,468,949 | Jun 26, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 510 | $2.56 | $1.31K | 0.0% | 2,393,902 | Jun 25, 2026 | — | Form 4 |
| TANG KEVIN Other | Buy | 145,880 | $2.48 | $361.78K | 6.5% | 2,393,392 | Jun 25, 2026 | — | Form 4 |
What these mean— the action is the SEC’s own Form 4 transaction code. Only a buy or a sell is an open-market trade; the rest are transfers, awards and exercises, which is why they carry no price.
- Buy (P) — Open-market or private purchase
- Sell (S) — Open-market or private sale
- Option exercise (M) — Exercise or conversion of an exempt derivative
Disclaimer — Informational only — not investment advice. Insider transaction data is sourced from SEC Form 4 filings; market data from public feeds and may be delayed. The Insider Score is a proprietary score for research purposes and does not predict future performance. Always do your own research.