Every Form 4 that Atara Biotherape (ATRA) has filed with the SEC in the last 12 months is listed below, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A Form 4 covers the transactions officers, directors and large holders report, so if you follow ATRA and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full ATRA filings page.
Atara Biotherapeutics, Inc. (ATRA) director Brian N. Cherry reported purchasing common stock of the company. On September 4, 2026, he acquired 104,166 shares of Atara common stock at $9.60 per share, increasing his directly held position to 166,486 shares.
The shares were purchased from Atara through its sales agent under a Sales Agreement dated November 1, 2023. No Rule 10b5-1 trading plan is indicated for this transaction.
Atara Biotherapeutics, Inc. (ATRA) reported that President and CEO Nguyen AnhCo had 5,062 shares of common stock sold on August 17, 2026. According to the disclosure, these shares were sold automatically to satisfy tax withholding obligations upon vesting of restricted stock units under a sale-to-cover provision, at a broker-executed weighted average price. Following this transaction, Nguyen AnhCo directly holds 132,775 shares of Atara common stock.
Funds managed by Redmile Group, LLC exercised Atara Biotherapeutics pre-funded warrants on July 22, 2026 via a cashless exercise. The exercise delivered 195,211 shares of common stock to the funds, with 60 shares withheld to cover the exercise price. The funds continue to hold pre-funded warrants with low exercise prices ($0.0025 and $0.0001 per share), each limited by a 9.99% beneficial ownership blocker. Redmile and Jeremy Green report these as indirect holdings, disclaiming beneficial ownership beyond their pecuniary interest, and also correct prior warrant terms previously reported.
Cherry Brian N reported acquisition or exercise transactions in this Form 4 filing.
Atara Biotherapeutics director Brian N. Cherry received a grant of 24,000 shares of common stock on June 11, 2026 as a compensation award. The shares are in the form of restricted stock units that vest in three equal annual installments on the first, second, and third anniversaries of June 11, 2026, subject to his continuous service. Following this grant, Cherry directly holds 62,320 shares of Atara common stock.
HEIDEN WILLIAM K reported acquisition or exercise transactions in this Form 4 filing.
Atara Biotherapeutics director William K. Heiden received a grant of 12,000 shares of Common Stock in the form of restricted stock units as compensation. The award was recorded at a price of $0.00 per share and is not an open-market purchase.
These restricted stock units will vest on the earlier of June 9, 2027 or the date of the next annual meeting of stockholders, provided he maintains continuous service. Following this grant, Heiden directly holds 34,188 shares of Atara Biotherapeutics common stock.
Fust Matthew K reported acquisition or exercise transactions in this Form 4 filing.
Atara Biotherapeutics director Matthew K. Fust received an equity award of 12,000 shares of common stock in the form of restricted stock units. The award was granted at no cash cost and will vest on the earlier of June 9, 2027 or the next annual stockholder meeting, subject to his continuous service. Following this grant, he holds 30,188 shares directly.
Ciongoli Gregory Austin reported acquisition or exercise transactions in this Form 4 filing.
Atara Biotherapeutics director Gregory A. Ciongoli reported an equity compensation award and updated his indirect holdings. He received a grant of 12,000 shares of common stock as a restricted stock unit award at a price of $0.00 per share.
These restricted stock units vest on the earlier of June 9, 2027 or the date of the next annual meeting of stockholders, subject to his continuous service. The filing also reports 1,209,395 shares of common stock indirectly held by Adiumentum Capital Fund I LP, a Delaware limited partnership with which Ciongoli and its general partner are associated, while all parties disclaim beneficial ownership except to the extent of any pecuniary interest.
Atara Biotherapeutics President and CEO Nguyen AnhCo reported an automatic sale of common stock tied to equity compensation. On May 18, 2026, 5,241 shares of common stock were sold at a weighted average price of $9.1289 per share. According to the disclosure, the shares were sold automatically to satisfy tax withholding obligations triggered by the vesting of previously granted restricted stock units under a sale-to-cover provision, rather than as a discretionary open-market sale for portfolio reasons. Following this transaction, AnhCo directly holds 137,837 shares of Atara common stock.
Atara Biotherapeutics Chief Accounting Officer Yanina Grant-Huerta reported the sale of 2,414 shares of common stock. The shares were sold on May 18, 2026 at a weighted average price of $9.1286 per share, in multiple trades between $9.12 and $9.40.
According to the disclosure, these shares were sold automatically to satisfy tax withholding obligations tied to the vesting of previously granted restricted stock units under a sale-to-cover provision. After the transaction, Grant-Huerta directly holds 49,636 shares of Atara common stock.
Atara Biotherapeutics, Inc. reported an insider filing showing that investment entities associated with Panacea Innovation executed an open-market sale of 313,446 shares of common stock at a weighted average price of $10.0975 per share, with individual trades between $10.00 and $10.50. The shares sold were held by Panacea Venture Healthcare Fund II, L.P. Following the sale, entities associated with Panacea report indirect holdings of 1,011,000 shares in one position and 307,894 shares in another. James Huang and Panacea Innovation Limited may be deemed to share beneficial ownership of these fund holdings, but each expressly disclaims beneficial ownership.
EcoR1 Capital, LLC, a ten percent owner of Atara Biotherapeutics, reported an indirect open-market purchase of 507,407 shares of Common Stock at a weighted average price of $9.35 per share. The shares were bought by funds it advises, which now hold 1,552,000 shares in total.
Atara Biotherapeutics, Inc. reported an insider transaction in which entities associated with Panacea funds exercised warrants to acquire common stock indirectly. Panacea Opportunity Fund I, L.P. exercised 259,163 warrants at an exercise price of $0.0001 per share, converting them into the same number of Atara common shares.
In connection with this exercise, 5 common shares were withheld at a price of $5.23 per share to cover tax obligations, a non-market disposition. Following these transactions, indirect holdings reported for these affiliated entities totaled over one million Atara common shares, while the reporting persons formally disclaim beneficial ownership beyond what may be attributed through their roles.
Nguyen AnhCo reported acquisition or exercise transactions in this Form 4 filing.
Atara Biotherapeutics reported that President and CEO Nguyen AnhCo received a grant of 81,100 shares of common stock in the form of restricted stock units at no cash cost. These RSUs vest in eight equal quarterly installments beginning on the second Quarterly Vesting Date after March 9, 2026, and then on subsequent March 1, May 15, August 15, and November 15 vesting dates, subject to continued employment. Following this award, AnhCo directly holds 143,078 shares of Atara common stock.
Grant-Huerta Yanina reported acquisition or exercise transactions in this Form 4 filing.
Atara Biotherapeutics reported that Chief Accounting Officer Yanina Grant-Huerta received a grant of 20,300 restricted stock units (RSUs) of common stock at no cost. Following this award, she holds 52,050 shares of common stock directly.
The RSUs vest in eight equal installments of one-eighth each. Vesting begins on the second Quarterly Vesting Date after March 9, 2026 and continues on the next seven Quarterly Vesting Dates, subject to her continuous employment. Quarterly Vesting Dates are March 1, May 15, August 15, and November 15, or the first business day thereafter.
Atara Biotherapeutics Chief Accounting Officer Yanina Grant-Huerta reported open-market sales of 2,104 shares of common stock on March 2, 2026. The shares were sold automatically to cover tax withholding on vesting restricted stock units at weighted average prices around $5.08 per share. Following these transactions, she directly holds 31,750 shares, including 400 shares acquired through the company’s employee stock purchase plan.
Atara Biotherapeutics President and CEO Nguyen AnhCo sold 2,996 shares of common stock on March 2, 2026 to cover tax withholding on vested restricted stock units.
The shares were sold in open-market transactions at weighted average prices around $5.08 per share, and he now directly holds 61,978 common shares.
Panacea-affiliated investment funds reported an insider sale of Atara Biotherapeutics, Inc. common stock. On January 12, 2026, Panacea Venture Healthcare Fund II, L.P. sold 80,554 shares of Atara common stock in an open-market transaction at a weighted average price of $6.0707 per share, with individual trades ranging from $5.9888 to $6.2838.
After this sale, Panacea Venture Healthcare Fund II, L.P. held 1,324,446 shares of Atara common stock indirectly for the reporting persons, and Panacea Opportunity Fund I, L.P. held an additional 48,736 shares. Panacea Innovation Ltd and James Huang are reporting persons because of their control of the general partners of these funds and may be deemed to share beneficial ownership of these holdings, although each disclaims such beneficial ownership.
Atara Biotherapeutics (ATRA) President and CEO AnhCo Nguyen, who also serves as a director, reported an automatic sale of company common stock related to tax withholding on vested restricted stock units. On 11/17/2025, Nguyen sold 2,859 shares of common stock at a weighted average price of $13.186 per share and an additional 56 shares at a weighted average price of $13.188 per share. These transactions were carried out by a broker as part of a group sale for multiple employees to satisfy withholding tax liabilities tied to equity awards. Following the transactions, Nguyen directly beneficially owned 64,974 shares of Atara Biotherapeutics common stock.
Atara Biotherapeutics, Inc. reported insider share sales by an officer related to tax withholding. The company’s Chief Accounting Officer, Yanina Grant-Huerta, reported three sales of Atara common stock on 11/17/2025 totaling 1,804 shares at weighted average prices between $13.186 and $13.191 per share. After these transactions, she beneficially owned 33,454 shares of common stock directly.
The filing explains that the shares were sold automatically under a sale-to-cover provision to satisfy tax withholding obligations upon the vesting of previously granted restricted stock units, with prices reflecting broker-handled sales for a group of employees on that date.