Atara Biotherapeutics (NASDAQ: ATRA) holder files Rule 144 sale notice

Rhea-AI Filing Summary

Atara Biotherapeutics, Inc. (ATRA) has a shareholder filing a notice of proposed sales of common stock under Rule 144. The notice lists planned sales of 40,000 shares through Cantor Fitzgerald, 20,000 shares through Jefferies, and 20,554 shares through JP Morgan, all as common stock traded on NASDAQ, with an approximate sale date of 01/12/2026. The corresponding aggregate market values are stated as 235,200, 117,600.00, and 120,858.00, respectively. The filing notes that 7,210,235 shares of common stock are outstanding. The seller reports having acquired 1,405,000 shares of common stock on 08/15/2025, through multiple open market purchases from January 2025 through August 2025 and a registered direct financing in May 2025, paid in cash.

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK
Filer CCC
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer

SEC File Number

Address of Issuer

Phone

Name of Person for Whose Account the Securities are To Be Sold

See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.

Relationship to Issuer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common Stock	Cantor Fitzgerald 110 East 59th Street NY NY 10022	40000	235200	7210235	01/12/2026	NASDAQ
Common Stock	Jefferies 520 Madison Avenue NY NY 10022	20000	117600.00	7210235	01/12/2026	NASDAQ
Common Stock	JP Morgan 270 Park Avenue NY NY 10017	20554	120858.00	7210235	01/12/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common Stock	08/15/2025	The Common Stock was purchased in multiple open market transactions from January 2025 through August 2025 as well as a registered direct financing in May 2025.	Brokerage transactions			1405000	08/15/2025	Cash

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Nothing to Report

144: Remarks and Signature

Remarks

Date of Notice

ATTENTION:

The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.

Signature

ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)

FAQ

What does the Atara Biotherapeutics (ATRA) Form 144 filing disclose?

The Form 144 discloses that a shareholder intends to sell shares of Atara Biotherapeutics, Inc. common stock under Rule 144. The notice lists specific share amounts, market values, brokers to be used, and an approximate sale date, along with information on when and how the shares were originally acquired.

How many Atara Biotherapeutics (ATRA) shares are planned to be sold and through which brokers?

The notice lists planned sales of 40,000 shares of common stock through Cantor Fitzgerald, 20,000 shares through Jefferies, and 20,554 shares through JP Morgan. All are described as common stock to be sold on NASDAQ with an approximate sale date of 01/12/2026.

What aggregate market values are associated with the planned Atara Biotherapeutics share sales?

The filing lists aggregate market values of 235,200 for the 40,000-share block through Cantor Fitzgerald, 117,600.00 for the 20,000-share block through Jefferies, and 120,858.00 for the 20,554-share block through JP Morgan.

How and when were the Atara Biotherapeutics (ATRA) shares to be sold under Rule 144 acquired?

The shareholder reports acquiring 1,405,000 shares of common stock on 08/15/2025. The shares were obtained in multiple open market transactions from January 2025 through August 2025 and in a registered direct financing in May 2025, with payment made in cash.

How many Atara Biotherapeutics common shares are outstanding according to this notice?

The securities information section states that the number of shares or other units outstanding of Atara Biotherapeutics common stock is 7,210,235.

What representation does the seller make regarding information about Atara Biotherapeutics?

By signing the notice, the person for whose account the securities are to be sold represents that they do not know any material adverse information about the current and prospective operations of the issuer that has not been publicly disclosed. The notice also warns that intentional misstatements or omissions of facts constitute federal criminal violations.