NASDAQ:ATRA

Atara Biotherapeutics Stock Insider Trading

Healthcare > Biotechnology

Buy ATRA

*Your capital is at risk

$9.63

-0.270 (-2.73%)

At Close: Jun 03, 2026

Atara Biotherapeutics Stock Insider Power

Based on the 100 latest insides trades, we have calculated the insider power to be positive at 54.67. In total, the insiders bought 9.54M and sold 448.96K ATRA shares in the last 100 trades. The insider score can be negative despite buy/sell ratio being positive. The score focuses on the quality of the trades.

Insider Power (Last 100 transactions)	54.67
● Buy	9.54M shares
● Sell	448.96K shares
50% Buy Activity Negligible or No Correlation
Sell Signal Low Confidence May 07, 2026 Analysis Breakdown: Signal is highly questionable due to a strongly contradictory positive Insider Power Score of 54.67. Confidence increased due to high data reliability score of 100.

Historical Insider Trades

Date	Type	Person	Role	Amount
May 16, 2025 Buy	Warrants (right to buy) A-Award	Adiumentum Capital Fund I Lp See Remarks	Director	227 000 Value: $23
May 16, 2025 Buy	Common Stock A-Award	Adiumentum Capital Fund I Lp See Remarks	Director	75 572 Value: $499.5K
Mar 31, 2025 Buy	Common Stock	Grant-huerta Yanina Chief Accounting Officer	Officer	0 Value: $0
Mar 31, 2025 Buy	Employee Stock Option (Right to Buy)	Grant-huerta Yanina Chief Accounting Officer	Officer	550 Value: $53.8K
Mar 31, 2025 Buy	Employee Stock Option (Right to Buy)	Grant-huerta Yanina Chief Accounting Officer	Officer	550 Value: $53.8K
Mar 31, 2025 Buy	Common Stock	Grant-huerta Yanina Chief Accounting Officer	Officer	0 Value: $0
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	8 961 Value: $875.9K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	543 Value: $138.6K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	154 Value: $46.8K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	350 Value: $149.7K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	1 900 Value: $1.89M
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	331 Value: $32.4K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	262 Value: $66.9K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	460 Value: $442.4K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	460 Value: $442.4K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	262 Value: $66.9K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	331 Value: $32.4K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	1 900 Value: $1.89M
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	350 Value: $149.7K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	154 Value: $46.8K
Mar 31, 2025 Sell	Employee Stock Option (Right to Buy) D-Return	Hyllengren Eric J Former EVP, CFO & COO	C-Suite Officer	543 Value: $138.6K
Jul 31, 2024 Buy	Employee Stock Option (Right to Buy)	Grant-huerta Yanina Chief Accounting Officer	Officer	275 Value: $3K
Jul 31, 2024 Buy	Employee Stock Option (Right to Buy)	Grant-huerta Yanina Chief Accounting Officer	Officer	275 Value: $3K
Apr 06, 2024 Buy	Employee Stock Option (Right to Buy)	Grant-huerta Yanina Chief Accounting Officer	Officer	800 Value: $158.4K
Apr 06, 2024 Buy	Employee Stock Option (Right to Buy)	Grant-huerta Yanina Chief Accounting Officer	Officer	800 Value: $158.4K

About Insider Power

Insider Power is a proprietary algorithm developed by StockInvest.us to evaluate the significance of insider transactions. The calculation considers the size, type, and timing of transactions, as well as the insider’s role within the company.

It is important to note that, in general, there is little to no correlation between insider transactions and short-term stock price movements. In one of our studies, only 0.22%^* of stocks with insider activity showed a measurable correlation — and even then, it was unclear whether the effect was caused by insider actions or simply by the stock’s broader trend.

While our algorithms are designed to highlight potentially meaningful signals, these cannot be regarded as statistically significant on their own. Insider trading activity should therefore be seen as informative rather than as direct trading guidance. The Insider Power metric was created to present this information in a clearer and more accessible way, helping investors better understand the possible context of insider activity.

* October 6th, 2025 - Tested on 5562 stocks

ABOUT ATARA BIOTHERAPEUTICS

Atara Biotherapeutics, Inc., an off-the-shelf T-cell immunotherapy company, develops treatments for patients with cancer, autoimmune, and viral diseases in the United States. It is developing tabelecleucel, a T-cell immunotherapy that is Phase 3 clinical trials for the treatment of epstein-barr virus (EBV) driven post-transplant lymphoproliferative disease, as well as hematologic and solid tumors, including nasopharyngeal carcinoma. The company i...

Read Full Profile Here