$ATRA

Cherry Brian N purchased 104,166 shares of Atara Biotherapeutics, Inc. (ATRA) at $9.60 ($1.00M total) on 2026-09-04.

Atara Biotherapeutics, Inc. (ATRA) filed an SEC Form 8-K — Results of Operations and Financial Condition. Exhibit 99.1 Atara Biotherapeutics Announces Second Quarter 2026 Financial Results and Operational Progress Productive Type A Meeting with FDA for tabelecleucel FDA guidance provided on resubmission of tabelecleucel BLA Year over Year costs and operating expenses reduction of 87%

Atara Biotherapeutics, Inc. (ATRA) filed an SEC Form 8-K — Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers. 8-K 0001604464 false 0001604464 2026-06-22 2026-06-22 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 22,

Atara Biotherapeutics, Inc. (ATRA) filed an SEC Form 8-K — Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers. false 0001604464 0001604464 2026-06-09 2026-06-09 iso4217:USD xbrli:shares iso4217:USD xbrli:shares UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Repor

Atara Biotherapeutics (ATRA) filed a Form 144 SEC notice detailing the settlement of 13,887 vested Restricted Stock Units (RSUs) on May 15, 2026, under an S-8 registration plan, representing equity compensation. The filing also notes a previous sale of 2,996 shares on March 2, 2026, with associated proceeds of $15,237.36. This indicates routine equity compensation activity rather than discretionary open-market sales.

James Huang, a director and ten percent owner of Atara Biotherapeutics, Inc., along with Panacea Innovation Ltd., sold 313,446 shares of common stock totaling $3,165,020 on May 7, 2026, at an average price of $10.0975 per share. This sale follows significant stock volatility and comes as InvestingPro analysis suggests the stock is overvalued. Meanwhile, Atara Biotherapeutics is actively working with Pierre Fabre Pharmaceuticals to advance the resubmission of the biologics license application for tabelecleucel, having received positive guidance from the FDA regarding study design.

Funds associated with Panacea Innovation, and tied to Atara Biotherapeutics director James Huang, sold 313,446 shares of Atara common stock at a weighted average price of $10.0975 per share. Despite the sale, Panacea-related entities retain indirect holdings of over 1.3 million shares. Both James Huang and Panacea Innovation Limited disclaim beneficial ownership of these fund holdings.

Atara Biotherapeutics (ATRA) has been upgraded from Hold to Buy by Canaccord Genuity analyst John Newman, with the price target significantly raised to $13.00 from $6.00. The company is considered undervalued by 25.9% according to GuruFocus, although its profitability remains a concern. This upgrade suggests increased confidence in ATRA's future growth despite past market struggles, presenting a potential opportunity for investors.

Bronstein, Gewirtz & Grossman, LLC has announced that a class action lawsuit has been filed against Atara Biotherapeutics, Inc. (NASDAQ: ATRA) and its officers. The lawsuit alleges that Atara made false or misleading statements regarding manufacturing issues and deficiencies in the ALLELE study, overstating regulatory prospects for tabelecleucel. Investors who purchased Atara securities between May 20, 2024, and January 9, 2026, are encouraged to join the case, with a lead plaintiff deadline of May 22, 2026.

The Gross Law Firm has issued a shareholder alert for Atara Biotherapeutics, Inc. (NASDAQ: ATRA), announcing a lead plaintiff deadline of May 22, 2026, for a securities class action lawsuit. The lawsuit alleges that during the period of May 20, 2024, to January 9, 2026, the company made false or misleading statements regarding manufacturing issues and the regulatory prospects of its drug tabelecleucel. Shareholders who purchased ATRA shares during this period are encouraged to contact the firm to potentially be appointed as lead plaintiff.