BOLD
Boundless Bio, Inc. · Healthcare · Market cap $55.5M
Insiders bought $295K net in the last 90 days ·1 seller, 1 buyer· latest Form 4 filed Oct 20, 2026
Insider Buying
$1.9M
reported purchases (SEC code P)
Insider Selling
$134K
reported sales (SEC code S)
Unique Insiders
3
in the rolling window
Latest filing
Oct 20, 2026
TANG KEVIN
Boundless Bio, Inc. (BOLD) has 10 SEC Form 4 filings (31 transaction rows) in the rolling window, disclosed by 3 distinct insiders. Most recent filing: Oct 20, 2026.
Inside the rolling window, 3 insiders at Boundless Bio, Inc. reported 21 open-market purchases totaling $1.9M and 3 open-market sales totaling $134K. The most active filer is 10% Owner TANG KEVIN with 22 filings. Insiders have net bought $1.7M over the trailing 6 months. The most recent open-market filing is a purchase of 118,185 shares by 10% Owner TANG KEVIN, dated Oct 16, 2026, worth $277K.
- Industry:Biotechnology
- CEO:Zachary Hornby
- Employees:28
- HQ:San Diego, CA, US
- IPO:2024-03-28
| Source | |||||||
|---|---|---|---|---|---|---|---|
| 10% Owner | Purchase | 118,185 | $277K | Oct 20 | +0.4% | SEC ↗ | |
| 10% Owner | Purchase | 31,069 | $73K | Oct 20 | +0.4% | SEC ↗ | |
| 10% Owner | Purchase | 220 | $521 | Oct 20 | +0.4% | SEC ↗ | |
| 10% Owner | Sale | 18,300 | $54K | Aug 28 | -13.8% | SEC ↗ | |
| 10% Owner | Purchase | 265 | $647 | Jul 21 | -1.6% | SEC ↗ | |
| 10% Owner | Purchase | 1,623 | $4K | Jul 21 | -1.6% | SEC ↗ | |
| 10% Owner | Purchase | 2,975 | $7K | Jul 21 | -1.6% | SEC ↗ | |
| 10% Owner | Purchase | 43,878 | $107K | Jul 17 | -1.6% | SEC ↗ | |
| 10% Owner | Purchase | 1,600 | $4K | Jul 17 | -1.6% | SEC ↗ | |
| 10% Owner | Purchase | 18,491 | $45K | Jul 17 | — | SEC ↗ | |
| 10% Owner | Purchase | 7 | $17 | Jul 13 | — | SEC ↗ | |
| 10% Owner | Purchase | 43,367 | $105K | Jul 13 | — | SEC ↗ | |
| 10% Owner | Purchase | 48,211 | $117K | Jul 13 | — | SEC ↗ | |
| 10% Owner | Purchase | 27,062 | $67K | Jul 9 | — | SEC ↗ | |
| 10% Owner | Purchase | 15,810 | $39K | Jul 9 | — | SEC ↗ | |
| 10% Owner | Purchase | 14,338 | $35K | Jul 9 | — | SEC ↗ | |
CRANDELL KEITHFirst filing | 10% Owner | Sale | 16,000 | $40K | Jul 6 | — | SEC ↗ |
ARCH Venture Fund IX, L.P.First filing | 10% Owner | Sale | 16,000 | $40K | Jul 6 | — | SEC ↗ |
| 10% Owner | Purchase | 26,030 | $66K | Jul 2 | — | SEC ↗ | |
| 10% Owner | Purchase | 71,612 | $178K | Jul 2 | — | SEC ↗ | |
| 10% Owner | Purchase | 9,821 | $24K | Jul 2 | — | SEC ↗ | |
| 10% Owner | Purchase | 146,390 | $363K | Jun 29 | — | SEC ↗ | |
| 10% Owner | Purchase | 75,181 | $192K | Jun 29 | — | SEC ↗ | |
| 10% Owner | Purchase | 64,762 | $160K | Jun 29 | — | SEC ↗ |
Earnings: last 7 quarters
Frequently asked questions
How many SEC Form 4 insider filings does BOLD have?
Boundless Bio, Inc. (BOLD) has 10 SEC Form 4 filings (31 transaction rows) in the rolling 365-day window, disclosed by 3 distinct insiders. Most recent filing: Oct 20, 2026.
When was the most recent SEC Form 4 filing for BOLD?
The most recent Form 4 filing for BOLD on Tracefour is dated Oct 20, 2026.
Who is the most active insider at BOLD?
The most active SEC Form 4 filer at BOLD in the rolling window is 10% Owner TANG KEVIN, with 22 filings.
What is the net insider flow at BOLD over the last 6 months?
Over the trailing 180 days, insiders at BOLD have net bought $1.7M based on SEC Form 4 disclosures.
What is the total insider buy and sell value at BOLD in the current window?
Inside the rolling window, insiders at BOLD bought $1.9M and sold $134K based on SEC Form 4 filings.
Can I get alerts for BOLD insider trading?
Yes. Tracefour sends a free email when a new SEC Form 4 purchase or sale is filed at Boundless Bio, Inc. (BOLD). Alerts are set per company from the page itself, there is no paid tier, and each email links to the original filing on SEC EDGAR.
Related companies
Boundless Bio, Inc. is in the Healthcare sector.