Form 4 for ATRA Atara Biotherapeutics, Inc.

Accepted 2026-03-04 00:00:00 ET · period of report 2026-03-02 · accession 0000905148-26-001144 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X	Filed	Traded	Ticker	Insider	Title	Type	Price	Qty	Owned	ΔOwn	Value
M	2026-03-04	2026-03-02	ATRA	Grant-Huerta Yanina	CAO	S - Sale	$5.08	-2,104	31.8K	-6%	-$10.7K

Purchase Sale Sale after option exercise All abbreviations

#	Table	Security	Date	Code	A/D	Shares	Price	Owned after	Own	Exercise / expiry	Underlying	Footnotes
1	Common	Common Stock	2026-03-02	S	D	377	$5.08	31,850	D	—	—	(F2) The sale price of the reporting person's shares represents the weighted average price of all shares sold by a broker on March 2, 2026 on behalf of a group of employees of the Issuer to satisfy the payment of withholding tax liability of such employees.
2	Common	Common Stock	2026-03-02	S	D	1,603	$5.08	32,227	D	—	—	(F2) The sale price of the reporting person's shares represents the weighted average price of all shares sold by a broker on March 2, 2026 on behalf of a group of employees of the Issuer to satisfy the payment of withholding tax liability of such employees.
3	Common	Common Stock	2026-03-02	S	D	24	$5.08	33,830	D	—	—	(F2) The sale price of the reporting person's shares represents the weighted average price of all shares sold by a broker on March 2, 2026 on behalf of a group of employees of the Issuer to satisfy the payment of withholding tax liability of such employees. (F3) This amount includes 400 shares purchased under the Issuer's Employee Stock Purchase Plan on November 28, 2025.
4	Common	Common Stock	2026-03-02	S	D	100	$5.08	31,750	D	—	—	(F2) The sale price of the reporting person's shares represents the weighted average price of all shares sold by a broker on March 2, 2026 on behalf of a group of employees of the Issuer to satisfy the payment of withholding tax liability of such employees.