United States Biotechnology & Medical Research

Atara Biotherapeutics Inc (ATRA)

Track

Atara Biotherapeutics Inc. saw significant insider activity over the last 90 days, characterized by a net negative executive position. While EcoR1 Capital, LLC executed a substantial purchase, 10% stockholder Panacea Innovation Ltd and key executives, including the CEO and CAO, engaged in multiple sales following the company's recent earnings report.
Ticker: ATRA Exchange: NSM
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• Purchase • Sale • Planned purchase • Planned sale Net purchase Net sale Buy signal Sell signal Earnings
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Top insiders
Trades
Nguyen AnhCo
President and CEO
2 sales — total 110,525 USD
Sale 18 May 2026
Value US$2,463,562.17 | Price 366.46 | Shares 7,052
Proposed sale 18 May 2026
Value US$2,206,952.95 | Price 39.21 | Shares 38,520
Sale 18 May 2026
Value US$3,537,205.70 | Price 480.06 | Shares 74,595
Proposed sale 18 May 2026
Value US$3,062,670.05 | Price 369.84 | Shares 5,465
Sale 7 May 2026
Value US$3,165,020.98 | Price 10.10 | Shares 313,446
Proposed sale 7 May 2026
Value US$3,165,020.99 | Price 10.10 | Shares 313,446
Buy 7 May 2026
Value US$4,744,255.45 | Price 9.35 | Shares 507,407
Sale 2 Mar 2026
Value US$508.30 | Price 5.08 | Shares 100
Sale 2 Mar 2026
Value US$1,915.91 | Price 5.08 | Shares 377
Sale 2 Mar 2026
Value US$8,144.84 | Price 5.08 | Shares 1,603
Planned sale 2 Mar 2026
Value US$121.85 | Price 5.08 | Shares 24
Proposed sale 2 Mar 2026
Value US$12,764.10 | Price 5.42 | Shares 2,355
Sale 2 Mar 2026
Value US$7,335.45 | Price 5.09 | Shares 1,442
Sale 2 Mar 2026
Value US$6,601.63 | Price 5.09 | Shares 1,298
Sale 2 Mar 2026
Value US$294.64 | Price 5.08 | Shares 58
Sale 2 Mar 2026
Value US$1,005.64 | Price 5.08 | Shares 198
Proposed sale 2 Mar 2026
Value US$18,184.10 | Price 5.42 | Shares 3,355
Sale 12 Jan 2026
Value US$489,019.17 | Price 6.07 | Shares 80,554
Proposed sale 12 Jan 2026
Value US$120,858.00 | Price 5.88 | Shares 20,554
Proposed sale 12 Jan 2026
Value US$117,600.00 | Price 5.88 | Shares 20,000
Proposed sale 12 Jan 2026
Value US$235,200.00 | Price 5.88 | Shares 40,000
Sale 17 Nov 2025
Value US$976.13 | Price 13.19 | Shares 74
Sale 17 Nov 2025
Value US$1,120.98 | Price 13.19 | Shares 85
Sale 17 Nov 2025
Value US$21,690.97 | Price 13.19 | Shares 1,645
Proposed sale 17 Nov 2025
Value US$28,469.44 | Price 13.76 | Shares 2,069
Sale 17 Nov 2025
Value US$738.53 | Price 13.19 | Shares 56
Sale 17 Nov 2025
Value US$37,698.77 | Price 13.19 | Shares 2,859
Proposed sale 17 Nov 2025
Value US$46,040.96 | Price 13.76 | Shares 3,346
Sale 18 Aug 2025
Value US$18,819.54 | Price 11.62 | Shares 1,620
Sale 18 Aug 2025
Value US$14,878.82 | Price 11.62 | Shares 1,281
Sale 18 Aug 2025
Value US$661.94 | Price 11.61 | Shares 57
Proposed sale 18 Aug 2025
Value US$41,122.34 | Price 12.29 | Shares 3,346
Sale 18 Aug 2025
Value US$19,372.15 | Price 11.61 | Shares 1,668
Sale 18 Aug 2025
Value US$998.72 | Price 11.61 | Shares 86
Sale 18 Aug 2025
Value US$638.50 | Price 11.61 | Shares 55
Proposed sale 18 Aug 2025
Value US$25,169.92 | Price 12.29 | Shares 2,048
Buy 15 Aug 2025
Value US$670,422.50 | Price 12.19 | Shares 55,000
Buy 17 Jul 2025
Value US$186,372.00 | Price 9.64 | Shares 19,335
Sale 16 May 2025
Value US$22,155.59 | Price 6.76 | Shares 3,276
Proposed sale 16 May 2025
Value US$26,414.31 | Price 7.61 | Shares 3,471
Sale 16 May 2025
Value US$15,000.33 | Price 6.76 | Shares 2,218
Proposed sale 16 May 2025
Value US$17,883.50 | Price 7.61 | Shares 2,350
Sale 3 Mar 2025
Value US$23,307.01 | Price 7.00 | Shares 3,331
Proposed sale 3 Mar 2025
Value US$27,149.39 | Price 6.91 | Shares 3,929
Planned sale 3 Mar 2025
Value US$7,409.82 | Price 7.00 | Shares 1,059
Proposed sale 3 Mar 2025
Value US$8,602.95 | Price 6.91 | Shares 1,245
Sale 3 Mar 2025
Value US$8,473.37 | Price 7.00 | Shares 1,211
Proposed sale 3 Mar 2025
Value US$9,853.66 | Price 6.91 | Shares 1,426
Sale 18 Nov 2024
Value US$11,198.00 | Price 11.20 | Shares 1,000
Proposed sale 18 Nov 2024
Value US$13,344.00 | Price 12.00 | Shares 1,112
Sale 18 Nov 2024
Value US$18,633.47 | Price 11.20 | Shares 1,664
Proposed sale 18 Nov 2024
Value US$22,284.00 | Price 12.00 | Shares 1,857
Sale 18 Nov 2024
Value US$15,274.07 | Price 11.20 | Shares 1,364
Proposed sale 18 Nov 2024
Value US$18,204.00 | Price 12.00 | Shares 1,517
Proposed sale 18 Nov 2024
Value US$16,104.00 | Price 12.00 | Shares 1,342
Sale 16 Aug 2024
Value US$875.29 | Price 6.63 | Shares 132
Planned sale 16 Aug 2024
Value US$5,508.70 | Price 6.63 | Shares 831
Proposed sale 16 Aug 2024
Value US$8,926.26 | Price 8.02 | Shares 1,113
Sale 16 Aug 2024
Value US$371.34 | Price 6.63 | Shares 56
Sale 16 Aug 2024
Value US$1,969.11 | Price 6.63 | Shares 297
Sale 16 Aug 2024
Value US$9,731.37 | Price 6.63 | Shares 1,468
Proposed sale 16 Aug 2024
Value US$16,954.28 | Price 8.02 | Shares 2,114
Sale 16 Aug 2024
Value US$1,829.88 | Price 6.63 | Shares 276
Sale 16 Aug 2024
Value US$18,309.30 | Price 6.63 | Shares 2,762
Proposed sale 16 Aug 2024
Value US$28,270.50 | Price 8.02 | Shares 3,525
Sale 16 Aug 2024
Value US$192.30 | Price 6.63 | Shares 29
Sale 16 Aug 2024
Value US$6,900.79 | Price 6.63 | Shares 1,041
Proposed sale 16 Aug 2024
Value US$9,936.78 | Price 8.02 | Shares 1,239
Sale 16 Aug 2024
Value US$590.16 | Price 6.63 | Shares 89
Sale 16 Aug 2024
Value US$1,272.96 | Price 6.63 | Shares 192
Planned sale 16 Aug 2024
Value US$5,813.63 | Price 6.63 | Shares 877
Proposed sale 16 Aug 2024
Value US$10,762.84 | Price 8.02 | Shares 1,342
Sale 16 May 2024
Value US$26,468.68 | Price 0.62 | Shares 42,899
Sale 16 May 2024
Value US$26,468.68 | Price 0.62 | Shares 42,899
Sale 16 May 2024
Value US$19,991.42 | Price 0.62 | Shares 32,401
Abbreviations B: Buy, S: Sell, PP: Planned purchase, PlS: Planned sale, PrS: Proposed sale, O: Option / Other
Notification date Transaction date B/S Transaction type Insider and/or position Nb. shares
Price
Value 		Number of shares Price Value Details
2026-05-20 2026-05-18 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
7,052 -28.9%
366.46
US$2,463,562 		7,052 -28.9% 366.46 US$2,463,562
2026-05-20 2026-05-18 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
74,595 -34.9%
480.06
US$3,537,206 		74,595 -34.9% 480.06 US$3,537,206
2026-05-18 2026-05-18 PrS Proposed sale
3.3
Nguyen AnhCo

Director; Officer

Executive Director
38,520
39.21
US$2,206,953 		38,520 39.21 US$2,206,953
2026-05-18 2026-05-18 PrS Proposed sale
2.0
Grant-Huerta Yanina

Officer

Officer
2,754
10.48
US$28,862 		2,754 10.48 US$28,862
2026-05-11 2026-05-07 S Sale
2.1
Panacea Innovation Ltd
Large shareholder
313,446 -23.7%
10.10
US$3,165,021 		313,446 -23.7% 10.10 US$3,165,021
2026-05-11 2026-05-07 B Purchase
3.1
EcoR1 Capital, LLC
Large shareholder
507,407 +48.6%
9.35
US$4,744,255 		507,407 +48.6% 9.35 US$4,744,255
2026-05-07 2026-05-07 PrS Proposed sale
2.1
Panacea Innovation Ltd

10% Stockholder

Large shareholder
313,446
10.10
US$3,165,021 		313,446 10.10 US$3,165,021
2026-03-04 2026-03-02 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
100 -0.3%
5.08
US$508 		100 -0.3% 5.08 US$508
2026-03-04 2026-03-02 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
377 -1.2%
5.08
US$1,916 		377 -1.2% 5.08 US$1,916
2026-03-04 2026-03-02 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
1,603 -4.7%
5.08
US$8,145 		1,603 -4.7% 5.08 US$8,145
2026-03-04 2026-03-02 PlS Planned sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
24 -0.1%
5.08
US$122 		24 -0.1% 5.08 US$122
2026-03-04 2026-03-02 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
1,442 -2.3%
5.09
US$7,335 		1,442 -2.3% 5.09 US$7,335
2026-03-04 2026-03-02 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
1,298 -2.0%
5.09
US$6,602 		1,298 -2.0% 5.09 US$6,602
2026-03-04 2026-03-02 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
58 -0.1%
5.08
US$295 		58 -0.1% 5.08 US$295
2026-03-04 2026-03-02 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
198 -0.3%
5.08
US$1,006 		198 -0.3% 5.08 US$1,006
2026-03-02 2026-03-02 PrS Proposed sale
3.3
Nguyen AnhCo

Director; Officer

Executive Director
3,355
5.42
US$18,184 		3,355 5.42 US$18,184
2026-03-02 2026-03-02 PrS Proposed sale
2.0
Grant-Huerta Yanina

Officer

Officer
2,355
5.42
US$12,764 		2,355 5.42 US$12,764
2026-01-14 2026-01-12 S Sale
2.1
Panacea Innovation Ltd
Large shareholder
80,554 -5.7%
6.07
US$489,019 		80,554 -5.7% 6.07 US$489,019
2026-01-12 2026-01-12 PrS Proposed sale
2.1
Panacea Innovation Ltd

10% Stockholder

Large shareholder
20,554
5.88
US$120,858 		20,554 5.88 US$120,858
2026-01-12 2026-01-12 PrS Proposed sale
2.1
Panacea Innovation Ltd

10% Stockholder

Large shareholder
20,000
5.88
US$117,600 		20,000 5.88 US$117,600
2026-01-12 2026-01-12 PrS Proposed sale
2.1
Panacea Innovation Ltd

10% Stockholder

Large shareholder
40,000
5.88
US$235,200 		40,000 5.88 US$235,200
2025-11-19 2025-11-17 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
74 -0.2%
13.19
US$976 		74 -0.2% 13.19 US$976
2025-11-19 2025-11-17 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
85 -0.3%
13.19
US$1,121 		85 -0.3% 13.19 US$1,121
2025-11-19 2025-11-17 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
1,645 -4.7%
13.19
US$21,691 		1,645 -4.7% 13.19 US$21,691
2025-11-19 2025-11-17 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
56 -0.1%
13.19
US$739 		56 -0.1% 13.19 US$739
2025-11-19 2025-11-17 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
2,859 -4.2%
13.19
US$37,699 		2,859 -4.2% 13.19 US$37,699
2025-11-17 2025-11-17 PrS Proposed sale
3.3
Nguyen AnhCo

Director; Officer

Executive Director
3,346
13.76
US$46,041 		3,346 13.76 US$46,041
2025-11-17 2025-11-17 PrS Proposed sale
2.0
Grant-Huerta Yanina

Officer

Officer
2,069
13.76
US$28,469 		2,069 13.76 US$28,469
2025-08-20 2025-08-18 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
1,620 -2.3%
11.62
US$18,820 		1,620 -2.3% 11.62 US$18,820
2025-08-20 2025-08-18 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
1,281 -1.8%
11.62
US$14,879 		1,281 -1.8% 11.62 US$14,879
2025-08-20 2025-08-18 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
57 -0.1%
11.61
US$662 		57 -0.1% 11.61 US$662
2025-08-20 2025-08-18 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
1,668 -4.5%
11.61
US$19,372 		1,668 -4.5% 11.61 US$19,372
2025-08-20 2025-08-18 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
86 -0.2%
11.61
US$999 		86 -0.2% 11.61 US$999
2025-08-20 2025-08-18 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
55 -0.1%
11.61
US$638 		55 -0.1% 11.61 US$638
2025-08-18 2025-08-18 PrS Proposed sale
3.3
Nguyen AnhCo

Director; Officer

Executive Director
3,346
12.29
US$41,122 		3,346 12.29 US$41,122
2025-08-18 2025-08-18 PrS Proposed sale
2.0
Grant-Huerta Yanina

Officer

Officer
2,048
12.29
US$25,170 		2,048 12.29 US$25,170
2025-08-19 2025-08-15 B Purchase
2.1
Panacea Innovation Ltd
Large shareholder
55,000 +4.1%
12.19
US$670,422 		55,000 +4.1% 12.19 US$670,422
2025-07-21 2025-07-17 B Purchase
2.1
Panacea Innovation Ltd
Large shareholder
19,335 +1.5%
9.64
US$186,372 		19,335 +1.5% 9.64 US$186,372
2025-05-20 2025-05-16 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
3,276 -4.4%
6.76
US$22,156 		3,276 -4.4% 6.76 US$22,156
2025-05-20 2025-05-16 S Sale
2.0
Grant-Huerta Yanina

Chief Accounting Officer

Officer
2,218 -5.6%
6.76
US$15,000 		2,218 -5.6% 6.76 US$15,000
2025-05-16 2025-05-16 PrS Proposed sale
3.3
Nguyen AnhCo

Director; Officer

Executive Director
3,471
7.61
US$26,414 		3,471 7.61 US$26,414
2025-05-16 2025-05-16 PrS Proposed sale
2.0
Grant-Huerta Yanina

Officer

Officer
2,350
7.61
US$17,884 		2,350 7.61 US$17,884
2025-03-05 2025-03-03 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
3,331 -4.3%
7.00
US$23,307 		3,331 -4.3% 7.00 US$23,307
2025-03-05 2025-03-03 PlS Planned sale
4.1
Henrich Jill

EVP, Chief Regulatory Officer

Officer
1,059 -5.4%
7.00
US$7,410 		1,059 -5.4% 7.00 US$7,410
2025-03-05 2025-03-03 S Sale
3.8
Hyllengren Eric J

EVP, CFO and COO

Officer
1,211 -2.1%
7.00
US$8,473 		1,211 -2.1% 7.00 US$8,473
2025-03-03 2025-03-03 PrS Proposed sale
3.3
Nguyen AnhCo

Officer; Director

Executive Director
3,929
6.91
US$27,149 		3,929 6.91 US$27,149
2025-03-03 2025-03-03 PrS Proposed sale
3.8
Hyllengren Eric J

Officer

Officer
1,426
6.91
US$9,854 		1,426 6.91 US$9,854
2025-03-03 2025-03-03 PrS Proposed sale
4.1
Henrich Jill

Officer

Officer
1,245
6.91
US$8,603 		1,245 6.91 US$8,603
2024-11-20 2024-11-18 S Sale
4.1
Henrich Jill

EVP, Chief Regulatory Officer

Officer
1,000 -4.9%
11.20
US$11,198 		1,000 -4.9% 11.20 US$11,198
2024-11-20 2024-11-18 S Sale
3.3
Nguyen AnhCo

President and CEO

Executive Director
1,664 -2.1%
11.20
US$18,633 		1,664 -2.1% 11.20 US$18,633
2024-11-20 2024-11-18 S Sale
3.8
Hyllengren Eric J

EVP, CFO and COO

Officer
1,364 -5.5%
11.20
US$15,274 		1,364 -5.5% 11.20 US$15,274
2024-11-18 2024-11-18 PrS Proposed sale
3.3
Nguyen AnhCo

Officer; Director

Executive Director
1,857
12.00
US$22,284 		1,857 12.00 US$22,284
2024-11-18 2024-11-18 PrS Proposed sale
4.0
Murugan Amar

Former Officer

Officer
1,342
12.00
US$16,104 		1,342 12.00 US$16,104
2024-11-18 2024-11-18 PrS Proposed sale
3.8
Hyllengren Eric J

Officer

Officer
1,517
12.00
US$18,204 		1,517 12.00 US$18,204
2024-11-18 2024-11-18 PrS Proposed sale
4.1
Henrich Jill

Officer

Officer
1,112
12.00
US$13,344 		1,112 12.00 US$13,344
2024-08-20 2024-08-16 S Sale
4.1
Henrich Jill

EVP, Global Head RA & Quality

Officer
132 -0.6%
6.63
US$875 		132 -0.6% 6.63 US$875
2024-08-20 2024-08-16 PlS Planned sale
4.1
Henrich Jill

EVP, Global Head RA & Quality

Officer
831 -3.9%
6.63
US$5,509 		831 -3.9% 6.63 US$5,509
2024-08-20 2024-08-16 S Sale
3.3
Nguyen AnhCo

EVP, Chief Sci. & Tech Officer

Officer
56 -0.2%
6.63
US$371 		56 -0.2% 6.63 US$371
2024-08-20 2024-08-16 S Sale
3.3
Nguyen AnhCo

EVP, Chief Sci. & Tech Officer

Officer
297 -0.9%
6.63
US$1,969 		297 -0.9% 6.63 US$1,969
2024-08-20 2024-08-16 S Sale
3.3
Nguyen AnhCo

EVP, Chief Sci. & Tech Officer

Officer
1,468 -4.1%
6.63
US$9,731 		1,468 -4.1% 6.63 US$9,731
2024-08-20 2024-08-16 S Sale
3.8
Touchon Pascal

President and CEO

Executive Director
276 -0.4%
6.63
US$1,830 		276 -0.4% 6.63 US$1,830
2024-08-20 2024-08-16 S Sale
3.8
Touchon Pascal

President and CEO

Executive Director
2,762 -3.8%
6.63
US$18,309 		2,762 -3.8% 6.63 US$18,309
2024-08-20 2024-08-16 S Sale
3.8
Hyllengren Eric J

EVP, CFO

Officer
29 -0.1%
6.63
US$192 		29 -0.1% 6.63 US$192
2024-08-20 2024-08-16 S Sale
3.8
Hyllengren Eric J

EVP, CFO

Officer
1,041 -4.0%
6.63
US$6,901 		1,041 -4.0% 6.63 US$6,901
2024-08-20 2024-08-16 S Sale
4.0
Murugan Amar

EVP, Chief Legal Officer

Officer
89 -0.3%
6.63
US$590 		89 -0.3% 6.63 US$590
2024-08-20 2024-08-16 S Sale
4.0
Murugan Amar

EVP, Chief Legal Officer

Officer
192 -0.7%
6.63
US$1,273 		192 -0.7% 6.63 US$1,273
2024-08-20 2024-08-16 PlS Planned sale
4.0
Murugan Amar

EVP, Chief Legal Officer

Officer
877 -3.1%
6.63
US$5,814 		877 -3.1% 6.63 US$5,814
2024-08-16 2024-08-16 PrS Proposed sale
3.8
Touchon Pascal

Director; Officer

Executive Director
3,525
8.02
US$28,270 		3,525 8.02 US$28,270
2024-08-16 2024-08-16 PrS Proposed sale
3.3
Nguyen AnhCo

Officer

Officer
2,114
8.02
US$16,954 		2,114 8.02 US$16,954
2024-08-16 2024-08-16 PrS Proposed sale
4.0
Murugan Amar

Officer

Officer
1,342
8.02
US$10,763 		1,342 8.02 US$10,763
2024-08-16 2024-08-16 PrS Proposed sale
3.8
Hyllengren Eric J

Officer

Officer
1,239
8.02
US$9,937 		1,239 8.02 US$9,937
2024-08-16 2024-08-16 PrS Proposed sale
4.1
Henrich Jill

Officer

Officer
1,113
8.02
US$8,926 		1,113 8.02 US$8,926
2024-05-20 2024-05-16 S Sale
3.3
Nguyen AnhCo

EVP, Chief Sci. & Tech Officer

Officer
42,899 -4.6%
0.62
US$26,469 		42,899 -4.6% 0.62 US$26,469
2024-05-20 2024-05-16 S Sale
3.3
Nguyen AnhCo

EVP, Chief Sci. & Tech Officer

Officer
42,899 -4.6%
0.62
US$26,469 		42,899 -4.6% 0.62 US$26,469
2024-05-20 2024-05-16 S Sale
4.0
Murugan Amar

EVP, Chief Legal Officer

Officer
32,401 -4.5%
0.62
US$19,991 		32,401 -4.5% 0.62 US$19,991
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