As of the latest Form 4 filed Jun 15, 2026.
What Atara Biotherapeutics Inc insiders — officers, directors and 10% owners — have bought and sold in their own stock, straight from their SEC Form 4 filings. Values are shares × the reported transaction price where both are disclosed.
Buys plotted up, sells down; bar height is the disclosed dollar value (shares × reported price). Our Form 4 history is only complete from mid-2026, so early months are sparse — the series fills in as more filings land. Open-market purchases and sales only.
Newest filing first — the 20 most recent filings for ATRA.
| Filed | Trade date | Insider | Transaction | Shares | Price | Value | 10b5-1 | Filing |
|---|---|---|---|---|---|---|---|---|
| 2026-06-15 | 2026-06-11 | Cherry Brian N Director | AAward | +24.0K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-06-11 | 2026-06-09 | HEIDEN WILLIAM K Director | AAward | +12.0K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-06-11 | 2026-06-09 | Fust Matthew K Director | AAward | +12.0K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-06-11 | 2026-06-09 | Ciongoli Gregory Austin Director | AAward | +12.0K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-05-20 | 2026-05-18 | Nguyen AnhCo President and CEO | SSale | −5.24K | $9.13 | $47.8K | No | Form 4 ↗ |
| 2026-05-20 | 2026-05-18 | Grant-Huerta Yanina Chief Accounting Officer | SSale | −2.41K | $9.13 | $22.0K | No | Form 4 ↗ |
| 2026-05-11 | 2026-05-07 | Panacea Innovation Ltd Director | SSale | −313K | $10.10 | $3.17M | No | Form 4 ↗ |
| 2026-05-11 | 2026-05-07 | EcoR1 Capital, LLC 10% owner | PPurchase | +507K | $9.35 | $4.74M | No | Form 4 ↗ |
| 2026-03-19 | 2026-03-17 | Panacea Innovation Ltd Director | FTax | −5.00 | $5.23 | $26.15 | No | Form 4 ↗ |
| 2026-03-19 | 2026-03-17 | Panacea Innovation Ltd, Director | MExercise | +259K | $0.00 | $25.92 | No | Form 4 ↗ |
| 2026-03-11 | 2026-03-09 | Nguyen AnhCo President and CEO | AAward | +81.1K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-03-11 | 2026-03-09 | Grant-Huerta Yanina Chief Accounting Officer | AAward | +20.3K | $0.00 | $0.00 | No | Form 4 ↗ |
| 2026-03-04 | 2026-03-02 | Grant-Huerta Yanina Chief Accounting Officer | SSale | −100.00 | $5.08 | $508.30 | No | Form 4 ↗ |
| 2026-03-04 | 2026-03-02 | Grant-Huerta Yanina, Chief Accounting Officer | SSale | −377.00 | $5.08 | $1.92K | No | Form 4 ↗ |
| 2026-03-04 | 2026-03-02 | Grant-Huerta Yanina, Chief Accounting Officer | SSale | −1.60K | $5.08 | $8.14K | No | Form 4 ↗ |
| 2026-03-04 | 2026-03-02 | Grant-Huerta Yanina, Chief Accounting Officer | SSale | −24.00 | $5.08 | $121.85 | No | Form 4 ↗ |
| 2026-03-04 | 2026-03-02 | Nguyen AnhCo President and CEO | SSale | −1.44K | $5.09 | $7.34K | No | Form 4 ↗ |
| 2026-03-04 | 2026-03-02 | Nguyen AnhCo, President and CEO | SSale | −1.30K | $5.09 | $6.60K | No | Form 4 ↗ |
| 2026-03-04 | 2026-03-02 | Nguyen AnhCo, President and CEO | SSale | −58.00 | $5.08 | $294.64 | No | Form 4 ↗ |
| 2026-03-04 | 2026-03-02 | Nguyen AnhCo, President and CEO | SSale | −198.00 | $5.08 | $1.01K | No | Form 4 ↗ |
Insiders — a company’s officers, directors and holders of more than 10% of its stock — must report any trade in that stock to the SEC on a Form 4 within two business days. Each row here is one transaction from those filings.
The transaction code tells you what happened: Purchase (P) and Sale (S) are open-market trades — the ones markets watch most; Award (A) is a granted stock or unit, Option exercise (M) converts options into shares, and Gift (G) is a transfer for no consideration. Awards, exercises and gifts are largely compensation or administrative, not a directional bet.
One caveat on sales: many are made under a Rule 10b5-1 plan scheduled months in advance, so a sale is not automatically a bearish signal. Insider activity is a noisy input — read it alongside the filings, not on its own.
See also ATRA’s full analysis or the market-wide insider trading feed. The tabs above jump to ATRA’s other SEC data.
Source: SEC Form 4 filings for ATRA, parsed from EDGAR. Transaction prices are as reported in the filing — SEC public-domain data, not market quotes. Values are shares × reported price where both are disclosed; grants and gifts often carry no price. A delayed record of what insiders reported, not a live position or a recommendation.
Research and education only — not financial advice. TENKis not a registered investment adviser or broker-dealer and gives no personalized advice. Every call is impersonal — identical for all users, generated on a schedule from SEC filings plus a delayed/third-party price feed — may be wrong or out of date, and is not a recommendation to buy or sell any security. The operator and an affiliated trading operation may hold or trade the securities TENK rates; see Disclosures. Past performance does not guarantee future results. Do your own research.