The Gross Law Firm Reminds Atara Biotherapeutics, Inc. Investors of the Pending Class Action Lawsuit With a Lead Plaintiff Deadline of May 22, 2026 - ATRA

NEW YORK, May 15, 2026 (GLOBE NEWSWIRE) -- The Gross Law Firm issues the following notice to shareholders of Atara Biotherapeutics, Inc. (NASDAQ: ATRA). Shareholders who purchased shares of ATRA during the class period listed are encouraged to contact the firm regarding possible lead plaintiff appointment.

GlobeNewsWire • a day ago

Atara Biotherapeutics, Inc. (ATRA) Shareholders Who Lost Money Have Opportunity to Lead Securities Fraud Lawsuit

BENSALEM, Pa., May 15, 2026 /PRNewswire/ -- The Law Offices of Howard G.

PRNewsWire • 16 hours ago

ATRA UPCOMING DEADLINE: Faruqi & Faruqi, LLP Reminds Atara Biotherapeutics (ATRA) Investors of Securities Class Action Deadline on May 22, 2026

Faruqi & Faruqi, LLP Securities Litigation Partner James (Josh) Wilson Encourages Investors Who Suffered Losses In Atara To Contact Him Directly To Discuss Their Options If you purchased or acquired securities in Atara between May 20, 2024 and January 9, 2026 and would like to discuss your legal rights, call Faruqi & Faruqi partner Josh Wilson directly at 877-247-4292 or 212-983-9330 (Ext. 1310). [You may also click here for additional information] New York, New York--(Newsfile Corp. - May 15, 2026) - Faruqi & Faruqi, LLP, a leading national securities law firm, is investigating potential claims against Atara Biotherapeutics, Inc. ("Atara" or the "Company") (NASDAQ: ATRA) and reminds investors of the May 22, 2026 deadline to seek the role of lead plaintiff in a federal securities class action that has been filed against the Company.

Newsfile Corp • a day ago

Bronstein, Gewirtz & Grossman LLC Urges Atara Biotherapeutics, Inc. Investors to Act: Class Action Filed Alleging Investor Harm

NEW YORK, May 14, 2026 (GLOBE NEWSWIRE) -- Bronstein, Gewirtz & Grossman, LLC, a nationally recognized investor-rights law firm, announces that a class action lawsuit has been filed against Atara Biotherapeutics, Inc. (NASDAQ: ATRA) and certain of its officers. This lawsuit seeks to recover damages against Defendants for alleged violations of the federal securities laws on behalf of all persons and entities that purchased or otherwise acquired Atara securities between May 20, 2024 and January 9, 2026, both dates inclusive (the “Class Period”).

GlobeNewsWire • May 14, 2026

ATARA DEADLINE: ROSEN, A RANKED AND LEADING LAW FIRM, Encourages Atara Biotherapeutics, Inc. Investors to Secure Counsel Before Important Deadline in Securities Class Action - ATRA

NEW YORK, May 14, 2026 (GLOBE NEWSWIRE) -- WHY: Rosen Law Firm, a global investor rights law firm, reminds purchasers of securities of Atara Biotherapeutics, Inc. (NASDAQ: ATRA) between May 20, 2024 and January 9, 2026, inclusive (the “Class Period”), of the important May 22, 2026 lead plaintiff deadline.

GlobeNewsWire • May 14, 2026

ATRA INVESTOR NOTICE: Faruqi & Faruqi, LLP Reminds Atara Biotherapeutics (ATRA) Investors of Securities Class Action Deadline on May 22, 2026

Faruqi & Faruqi, LLP Securities Litigation Partner James (Josh) Wilson Encourages Investors Who Suffered Losses In Atara To Contact Him Directly To Discuss Their Options If you purchased or acquired securities in Atara between May 20, 2024 and January 9, 2026 and would like to discuss your legal rights, call Faruqi & Faruqi partner Josh Wilson directly at 877-247-4292 or 212-983-9330 (Ext. 1310). [You may also click here for additional information] NEW YORK, May 14, 2026 /PRNewswire/ -- Faruqi & Faruqi, LLP, a leading national securities law firm, is investigating potential claims against Atara Biotherapeutics, Inc. ("Atara" or the "Company") (NASDAQ: ATRA) and reminds investors of the May 22, 2026 deadline to seek the role of lead plaintiff in a federal securities class action that has been filed against the Company.

PRNewsWire • May 14, 2026

Pomerantz Law Firm Announces the Filing of a Class Action Against Atara Biotherapeutics, Inc. and Certain Officers - ATRA

NEW YORK, May 14, 2026 /PRNewswire/ -- Pomerantz LLP announces that a class action lawsuit has been filed against Atara Biotherapeutics, Inc. ("Atara" or the "Company") (NASDAQ: ATRA) and certain officers. The class action, filed in the United States District Court for the Central District of California, and docketed under 26-cv-03083, is on behalf of a class consisting of all persons and entities other than Defendants that purchased or otherwise acquired Atara securities between May 20, 2024 and January 9, 2026, both dates inclusive (the "Class Period"), seeking to recover damages caused by Defendants' violations of the federal securities laws and to pursue remedies under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder, against the Company and certain of its top officials.

PRNewsWire • May 15, 2026

ATRA Investors Have Opportunity to Lead Atara Biotherapeutics, Inc. Securities Fraud Lawsuit with the Schall Law Firm

LOS ANGELES, May 13, 2026 (GLOBE NEWSWIRE) -- The Schall Law Firm , a national shareholder rights litigation firm, reminds investors of a class action lawsuit against Atara Biotherapeutics, Inc. (“Atara” or “the Company”) (NASDAQ: ATRA) violations of §§10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder by the U.S. Securities and Exchange Commission. Investors who purchased the Company's securities between May 20, 2024 and January 9, 2026, inclusive (the “Class Period”), are encouraged to contact the firm before May 22, 2026.

GlobeNewsWire • May 14, 2026

ATRA CLASS ACTION NOTICE: Faruqi & Faruqi, LLP Reminds Atara Biotherapeutics (ATRA) Investors of Securities Class Action Deadline on May 22, 2026

Faruqi & Faruqi, LLP Securities Litigation Partner James (Josh) Wilson Encourages Investors Who Suffered Losses In Atara To Contact Him Directly To Discuss Their Options If you purchased or acquired securities in Atara between May 20, 2024 and January 9, 2026 and would like to discuss your legal rights, call Faruqi & Faruqi partner Josh Wilson directly at 877-247-4292 or 212-983-9330 (Ext. 1310). [You may also click here for additional information] New York, New York--(Newsfile Corp. - May 13, 2026) - Faruqi & Faruqi, LLP, a leading national securities law firm, is investigating potential claims against Atara Biotherapeutics, Inc. ("Atara" or the "Company") (NASDAQ: ATRA) and reminds investors of the May 22, 2026 deadline to seek the role of lead plaintiff in a federal securities class action that has been filed against the Company.

Newsfile Corp • May 13, 2026

ATARA DEADLINE: ROSEN, A LONGSTANDING FIRM, Encourages Atara Biotherapeutics, Inc. Investors to Secure Counsel Before Important Deadline in Securities Class Action - ATRA

New York, New York--(Newsfile Corp. - May 13, 2026) - WHY: Rosen Law Firm, a global investor rights law firm, reminds purchasers of securities of Atara Biotherapeutics, Inc. (NASDAQ: ATRA) between May 20, 2024 and January 9, 2026, inclusive (the "Class Period"), of the important May 22, 2026 lead plaintiff deadline. SO WHAT: If you purchased Atara securities during the Class Period you may be entitled to compensation without payment of any out of pocket fees or costs through a contingency fee arrangement.

Newsfile Corp • May 13, 2026