Company profile
Atara Biotherapeutics, Inc. Insider Trading
ATRAEvery SEC Form 4 insider trading filing for Atara Biotherapeutics, Inc. (ATRA) 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
- Biological Products, (No Diagnostic Substances)
- CIK
- 0001604464
- Filings
- 93
- Insiders
- 24
- Last filing
- 2026-07-22
Activity summary
No insider transactions in the last 30 days. The most recent was on July 22, 2026, when Redmile Group, LLC bought 195,211 shares. 93 filings from 24 insiders are on record below.
Three year balance
Buy and sell value by quarter, Q4 23 to Q3 26. Atara Biotherapeutics, Inc. insiders are net buyers across the period shown.
Bars below the rule are sales, above are purchases. Largest quarter on the chart is $4.7M.
90 day insight
Over the last 90 days, Atara Biotherapeutics, Inc. insiders bought $0 (8 transactions) and sold $0 (1 transaction).
- Most active insider: Redmile Group, LLC with 5 transactions totaling $0.
Activity skews bullish — buys outpace sales.
Insider Transactions
Sourced from SEC EDGAR Form 4 filings. Updated hourly.
| Date | Insider | Company | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Jul 22, 2026 | Redmile Group, LLC | ATRA | Option Exercise | 195,211 | — | — |
| Jul 22, 2026 | Redmile Group, LLC | ATRA | Option Exercise | 101,089 | — | — |
| Jul 22, 2026 | Redmile Group, LLC | ATRA | Option Exercise | 55,387 | — | — |
| Jul 22, 2026 | Redmile Group, LLC | ATRA | Option Exercise | 38,735 | — | — |
| Jul 22, 2026 | Redmile Group, LLC | ATRA | Tax Withholding | 60 | — | — |
45 more transactions hidden
Free account · No credit card required
Building something? Get API access →
Query this yourself
The same rows, over the API.
curl "https://api.form4api.com/v1/transactions?ticker=ATRA" \
-H "X-Api-Key: $KEY"Top insiders
By total value filed.
Institutional Ownership
Top 13F-HR holders of Atara Biotherapeutics, Inc. as of 2026-06-30
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 →