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Company profile

Boundless Bio, Inc. Insider Trading

BOLD

Every SEC Form 4 insider trading filing for Boundless Bio, Inc. (BOLD) since April 2023 — open-market buys and sells by directors and officers, option exercises, and cluster activity, updated as each filing is reported to the SEC. Why 2023?

Exchange
Nasdaq
Sector
Pharmaceutical Preparations
CIK
0001782303
Filings
54
Insiders
34
Last filing
2026-08-26
SEC EDGAR ↗Yahoo Finance ↗Finviz ↗Stock Analysis ↗

Activity summary

Recent insider activity is bearish. Over the last 30 days, insiders net sold $54K across 1 transaction.

Three year balance

Buy and sell value by quarter, Q1 24 to Q3 26. Boundless Bio, Inc. insiders are net buyers across the period shown.

PurchasesSales
Q1 24$14.6MQ2 24Q3 24Q4 24Q1 25Q2 25Q3 25Q4 25Q1 26Q2 26Q3 26

Bars below the rule are sales, above are purchases. Largest quarter on the chart is $14.6M.

90 day insight

Over the last 90 days, Boundless Bio, Inc. insiders bought $1.5M (26 transactions) and sold $134K (3 transactions).

  • Most active insider: Kevin Tang with 23 transactions totaling $1.6M.
  • Largest single purchase: $362K by Kevin Tang on Jun 25, 2026.

Activity skews bullish — buys outpace sales.

Insider Transactions

Sourced from SEC EDGAR Form 4 filings. Updated hourly.

DateInsiderCompanyTypeSharesPriceValueReturn
Aug 26, 2026Kevin TangBOLD
Sale
18,300$2.97$54K+1.1% 1w
Jul 21, 2026Kevin TangBOLD
Purchase
2,975$2.44$7K+13.5% 1m
Jul 20, 2026Kevin TangBOLD
Purchase
1,623$2.44$4K+13.5% 1m
Jul 17, 2026Kevin TangBOLD
Purchase
265$2.44$647+13.5% 1m
Jul 16, 2026Kevin TangBOLD
Purchase
18,491$2.44$45K+15.5% 1m

45 more transactions hidden

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Top insiders

By total value filed.

Kevin TangChief Executive Officer23 filings+$1.5M
ARCH Venture Fund IX, L.P.10% owner2 filings−$23K
Keith Crandell10% owner2 filings−$23K

Institutional Ownership

Top 13F-HR holders of Boundless Bio, Inc. as of 2026-06-30

— stable
Total reported AUM
$329,693
QoQ change
—
Reporting period
2026-06-30
#1
BlackRock, Inc.
CIK 0002012383
$147,128
59K shares
#2
BlackRock, Inc.
CIK 0002012383
$63,888
26K shares
#3
China Universal Asset Management Co., Ltd.
CIK 0001906594
$42,250
17K shares

Data source: quarterly 13F-HR filings — institutional holders report positions within 45 days of quarter end. Joined with insider activity above — see who's loading up institutionally while insiders are trading. Full 13F-HR API →

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Form4API, StockholmNot affiliated with the SEC or EDGAR. Data sourced from public EDGAR filings. Not investment advice.

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