Stocks
ATRA Atara Biotherapeutics, Inc.

ATRA

Atara Biotherapeutics, Inc.

Company with tickers: ATRA

CIK

1604464

CUSIP

046513206

Shares Outstanding

8,178,114

Price Holdings Short Volume Short Interest Fails to Deliver SEC Filings Earnings Calls Insider Trading Congress Trades

Date	Insider	Role	Type	Shares	Price	Value	After
2026-03-17	Panacea Innovation Ltd	10% Owner	Other	1,324,446	—	—	1,324,446
2026-03-17	Panacea Innovation Ltd	10% Owner	Convert	259,163	$0.00	$26	307,899
2026-03-17	Panacea Innovation Ltd	10% Owner	Convert	259,163	$6.61	$1,713,042	0
2026-03-17	Panacea Innovation Ltd	10% Owner	Tax	5	$5.23	$26	307,894
2026-03-09	Nguyen AnhCo	Director, President and CEO	Award	81,100	—	—	143,078
2026-03-09	Grant-Huerta Yanina	Chief Accounting Officer	Award	20,300	—	—	52,050
2026-03-02	Grant-Huerta Yanina	Chief Accounting Officer	Sell	24	$5.08	$122	33,830
2026-03-02	Nguyen AnhCo	Director, President and CEO	Sell	198	$5.08	$1,006	64,776
2026-01-12	Panacea Innovation Ltd	10% Owner	Other	48,736	—	—	48,736
2026-01-12	Panacea Innovation Ltd	10% Owner	Sell	80,554	$6.07	$489,019	1,324,446
2025-11-28	Panacea Innovation Ltd	10% Owner	Convert	48,737	$0.00	$5	48,737
2025-11-28	Panacea Innovation Ltd	10% Owner	Convert	48,737	$6.61	$322,147	259,163
2025-11-28	Panacea Innovation Ltd	10% Owner	Tax	1	$14.03	$14	48,736
2025-11-28	Panacea Innovation Ltd	10% Owner	Other	1,405,000	—	—	1,405,000
2025-11-17	Nguyen AnhCo	Director, President and CEO	Sell	2,859	$13.19	$37,699	65,030
2025-11-17	Grant-Huerta Yanina	Chief Accounting Officer	Sell	1,645	$13.19	$21,691	33,613
2025-08-18	Nguyen AnhCo	Director, President and CEO	Sell	57	$11.61	$662	70,790
2025-08-18	Grant-Huerta Yanina	Chief Accounting Officer	Sell	55	$11.61	$638	37,012
2025-08-15	Panacea Innovation Ltd	10% Owner	Buy	55,000	$12.19	$670,423	1,405,000
2025-07-17	Panacea Innovation Ltd	10% Owner	Buy	19,335	$9.64	$186,372	1,350,000
2025-06-10	Gallagher Carol Giltner	Director	Award	7,828	—	—	33,012
2025-06-10	MALLIK AMEET	Director, Chief Executive Officer	Award	7,828	—	—	16,928
2025-06-10	HEIDEN WILLIAM K	Director	Award	7,828	—	—	22,188
2025-06-10	Fust Matthew K	Director	Award	7,828	—	—	18,188
2025-06-10	Touchon Pascal	Director	Award	7,828	—	—	77,955
2025-06-10	Roncarolo Maria Grazia	Director	Award	7,828	—	—	17,368
2025-05-16	Nguyen AnhCo	Director, President and CEO	Sell	3,276	$6.76	$22,156	70,847
2025-05-16	Adiumentum Capital Fund I LP	Director, 10% Owner	Award	227,000	$6.61	$1,500,447	377,193
2025-05-16	Adiumentum Capital Fund I LP	Director, 10% Owner	Award	75,572	$6.61	$499,531	1,209,395
2025-05-16	Grant-Huerta Yanina	Chief Accounting Officer	Sell	2,218	$6.76	$15,000	37,067
2025-05-16	Subramanian Nachiappan	Director	Other	0	—	—	0
2025-05-16	Panacea Innovation Ltd	10% Owner	Other	0	—	—	0
2025-05-16	Panacea Innovation Ltd	10% Owner	Other	1,330,665	—	—	1,330,665
2025-05-16	Redmile Group, LLC	10% Owner	Other	0	—	—	0
2025-05-16	Redmile Group, LLC	10% Owner	Other	0	—	—	0
2025-05-16	Redmile Group, LLC	10% Owner	Other	441,701	—	—	441,701
2025-03-31	Hyllengren Eric J	Chief Financial Officer	Other	1,900	—	—	0
2025-03-31	Grant-Huerta Yanina	Chief Accounting Officer	Other	39,285	—	—	39,285
2025-03-31	Grant-Huerta Yanina	Chief Accounting Officer	Other	0	—	—	0
2025-03-03	Henrich Jill	EVP, Chief Regulatory Officer	Sell	1,059	$7.00	$7,410	18,679
2025-03-03	Nguyen AnhCo	Director, President and CEO	Sell	3,331	$7.00	$23,307	74,123
2025-03-03	Hyllengren Eric J	Chief Financial Officer	Sell	1,211	$7.00	$8,473	56,231
2025-01-27	Hyllengren Eric J	Chief Financial Officer	Award	34,050	—	—	57,442
2024-11-18	Henrich Jill	EVP, Chief Regulatory Officer	Sell	1,000	$11.20	$11,198	19,378
2024-11-18	Hyllengren Eric J	Chief Financial Officer	Sell	1,364	$11.20	$15,274	23,392
2024-11-18	Nguyen AnhCo	Director, President and CEO	Sell	1,664	$11.20	$18,633	77,454
2024-09-09	Nguyen AnhCo	Director, President and CEO	Award	45,000	—	—	79,118
2024-09-03	Adiumentum Capital Fund I LP	Director, 10% Owner	Other	0	—	—	0
2024-09-03	Adiumentum Capital Fund I LP	Director, 10% Owner	Other	1,133,823	—	—	1,133,823
2024-08-16	Touchon Pascal	Director	Sell	2,762	$6.63	$18,309	70,403
2024-08-16	Nguyen AnhCo	Director, President and CEO	Sell	1,468	$6.63	$9,731	34,471
2024-08-16	Murugan Amar	EVP, Chief Legal Officer	Sell	877	$6.63	$5,814	27,108
2024-08-16	Hyllengren Eric J	Chief Financial Officer	Sell	1,041	$6.63	$6,901	24,785
2024-08-16	Henrich Jill	EVP, Chief Regulatory Officer	Sell	831	$6.63	$5,509	20,510
2024-08-12	Touchon Pascal	Director	Other	9,000	—	—	0
2024-05-16	Touchon Pascal	Director	Sell	81,506	$0.62	$50,289	1,829,146
2024-05-16	Nguyen AnhCo	Director, President and CEO	Sell	42,899	$0.62	$26,469	898,498
2024-05-16	Murugan Amar	EVP, Chief Legal Officer	Sell	32,401	$0.62	$19,991	695,120
2024-05-16	Hyllengren Eric J	Chief Financial Officer	Sell	28,648	$0.62	$17,676	645,671
2024-05-16	Henrich Jill	EVP, Chief Regulatory Officer	Sell	25,750	$0.62	$15,888	529,251
2024-03-31	Fust Matthew K	Director	Award	150,000	—	—	259,000
2024-03-31	HEIDEN WILLIAM K	Director	Award	150,000	—	—	359,000
2024-03-31	Roncarolo Maria Grazia	Director	Award	150,000	—	—	238,500
2024-03-31	Gallagher Carol Giltner	Director	Award	150,000	—	—	629,608
2024-03-31	MALLIK AMEET	Director, Chief Executive Officer	Award	150,000	—	—	227,500
2024-03-04	Touchon Pascal	Director	Sell	24,844	$0.72	$17,888	1,910,652
2024-03-04	Nguyen AnhCo	Director, President and CEO	Sell	10,746	$0.72	$7,737	941,397
2024-03-04	Murugan Amar	EVP, Chief Legal Officer	Sell	10,044	$0.72	$7,232	727,521
2024-03-04	Hyllengren Eric J	Chief Financial Officer	Sell	1,462	$0.72	$1,054	679,536
2024-03-04	Henrich Jill	EVP, Chief Regulatory Officer	Sell	3,879	$0.72	$2,793	555,001
2024-01-08	Touchon Pascal	Director	Award	1,280,000	—	—	1,935,496
2024-01-08	Nguyen AnhCo	Director, President and CEO	Award	675,000	—	—	952,143
2024-01-08	Murugan Amar	EVP, Chief Legal Officer	Award	475,000	—	—	737,565
2024-01-08	Hyllengren Eric J	Chief Financial Officer	Award	475,000	—	—	680,998
2024-01-08	Henrich Jill	EVP, Chief Regulatory Officer	Award	450,000	—	—	558,880
2023-11-16	Touchon Pascal	Director	Sell	20,409	$0.39	$7,939	655,496
2023-11-16	Nguyen AnhCo	Director, President and CEO	Sell	8,856	$0.39	$3,445	277,143
2023-11-16	Murugan Amar	EVP, Chief Legal Officer	Sell	8,307	$0.39	$3,231	257,084
2023-11-16	Joshi Manher	Chief Development Officer	Sell	12,287	$0.39	$4,780	171,284
2023-11-16	Hyllengren Eric J	Chief Financial Officer	Sell	11,958	$0.39	$4,652	205,998
2023-11-16	Henrich Jill	EVP, Chief Regulatory Officer	Sell	3,267	$0.39	$1,271	104,424
2023-11-14	Gallagher Carol Giltner	Director	Buy	90,980	$0.31	$28,186	459,418
2023-11-13	Gallagher Carol Giltner	Director	Buy	179,020	$0.22	$40,029	368,438
2023-11-10	HEIDEN WILLIAM K	Director	Buy	100,000	$0.25	$25,330	209,000
2023-11-10	DOBMEIER ERIC	Director	Buy	446,825	$0.23	$101,340	563,325
2023-08-16	Nguyen AnhCo	Director, President and CEO	Sell	5,849	$1.65	$9,663	295,276
2023-08-16	Joshi Manher	Chief Development Officer	Sell	3,202	$1.65	$5,290	187,344
2023-08-16	Henrich Jill	EVP, Chief Regulatory Officer	Sell	2,788	$1.65	$4,609	108,249
2023-08-16	Hyllengren Eric J	Chief Financial Officer	Sell	6,408	$1.65	$10,586	219,734
2023-08-16	Murugan Amar	EVP, Chief Legal Officer	Sell	5,050	$1.65	$8,343	269,013
2023-08-16	Touchon Pascal	Director	Sell	21,432	$1.65	$35,406	685,239
2023-06-27	Touchon Pascal	Director	Sell	14,291	$1.66	$23,723	706,671
2023-06-01	Henrich Jill	EVP, Chief Regulatory Officer	Other	0	—	—	0
2023-06-01	Henrich Jill	EVP, Chief Regulatory Officer	Other	111,037	—	—	111,037
2023-06-01	Joshi Manher	Chief Development Officer	Other	0	—	—	0
2023-06-01	Joshi Manher	Chief Development Officer	Other	190,546	—	—	190,546
2023-06-01	Nguyen AnhCo	Director, President and CEO	Other	301,125	—	—	301,125
2023-06-01	Nguyen AnhCo	Director, President and CEO	Other	0	—	—	0
2023-05-31	SEIDENBERG BETH C	Director	Other	1,822,228	—	—	1,822,228
2023-05-31	SEIDENBERG BETH C	Director	Award	79,500	—	—	79,500