ATRA insider buying
1 cluster buyAtara Biotherapeutics, Inc. · Healthcare
When two or more insiders at Atara Biotherapeutics, Inc. buy ATRA on the open market around the same time, that clustered conviction is one of the highest-signal patterns in SEC filing data. Below is every cluster we've detected in ATRA plus the full record of qualifying open-market buys, each parsed directly from Form 4 filings and linked back to the source on SEC EDGAR.
Detected clusters
- Jul 17 – Aug 15, 2025Detected Aug 15, 20252 insidersTotal bought$856.8KMarket cap$98.0M
All notable open-market buys in ATRA
Every open-market Form 4 purchase, newest first. Click an insider to see their full buying record across companies.
| Date | Insider | Shares | Price | Value | Filing |
|---|---|---|---|---|---|
| May 7, 2026 | 10% Owner | 507,407 | $9.35 | $4.7M | SEC ↗ |
| Aug 15, 2025 | Panacea Innovation Ltdcluster 10% Owner | 55,000 | $12.19 | $670.5K | SEC ↗ |
| Jul 17, 2025 | Huang Jamescluster Director, 10% Owner | 19,335 | $9.64 | $186.4K | SEC ↗ |
More Healthcare stocks with insider cluster buys
ATRA insider buying — FAQ
- Are insiders buying ATRA stock?
- Yes — 3 distinct insiders have bought ATRA (Atara Biotherapeutics, Inc.) on the open market, including 1 cluster buy where two or more insiders bought within a rolling window. The most recent qualifying activity was May 11, 2026.
- How much ATRA stock have insiders bought?
- Insiders have bought a combined $5.6M of ATRA across 3 open-market purchases, based on SEC Form 4 filings.
- What is an insider cluster buy in ATRA?
- A cluster buy is two or more distinct Atara Biotherapeutics, Inc. insiders — officers, directors, or 10% owners — each buying ATRA on the open market within a rolling window. ATRA has 1 detected cluster buy to date.
- Where does this ATRA insider trading data come from?
- Every figure is parsed directly from SEC Form 4 filings on EDGAR, and each purchase on this page links back to its original filing document.
How we track insider buying in ATRA
We continuously poll SEC EDGAR for new Form 4 filings and parse every open-market purchase (transaction code P). A cluster is recorded when two or more distinct insiders — officers, directors, or 10% owners — each buy ATRA within a rolling window. We track clusters at every company size, from micro-caps to mega-caps. Every figure on this page traces back to an official filing; open any row to jump straight to the source document. What counts as a cluster buy?
This page is informational and reflects public filing data. It is not investment advice or a recommendation regarding ATRA.