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
Jun 10, 2025 Buy	Common Stock A-Award	Mallik Ameet Director	Director	7 828 Value: $71.4K
Jun 10, 2025 Buy	Common Stock A-Award	Roncarolo Maria Grazia Director	Director	7 828 Value: $71.4K
Jun 10, 2025 Buy	Common Stock A-Award	Touchon Pascal Director	Director	7 828 Value: $71.4K
Jun 10, 2025 Buy	Common Stock A-Award	Fust Matthew K Director	Director	7 828 Value: $71.4K
Jun 10, 2025 Buy	Common Stock A-Award	Gallagher Carol Giltner Director	Director	7 828 Value: $71.4K
May 16, 2025 Buy	Common Stock J-Other	Subramanian Nachiappan	Director	0 Value: $0
May 16, 2025 Buy	Common Stock, par value $0.0001 per share	Redmile Group, Llc Director	Director	0 Value: $0
May 16, 2025 Buy	Cash-settled Swaps	Redmile Group, Llc Director	Director	4 872 Value: $45.4K
May 16, 2025 Buy	Pre-Funded Warrants to Purchase Common Stock	Redmile Group, Llc Director	Director	3 412 843 Value: $23.3M
May 16, 2025 Buy	Cash-settled Swaps	Redmile Group, Llc Director	Director	4 103 Value: $3.32M
May 16, 2025 Buy	Cash-settled Swaps	Redmile Group, Llc Director	Director	4 103 Value: $3.32M
May 16, 2025 Buy	Common Stock, par value $0.0001 per share	Redmile Group, Llc Director	Director	0 Value: $0
May 16, 2025 Buy	Common Stock J-Other	Subramanian Nachiappan	Director	0 Value: $0
May 16, 2025 Buy	Pre-Funded Warrants to Purchase Common Stock	Redmile Group, Llc Director	Director	3 412 843 Value: $23.3M
May 16, 2025 Buy	Cash-settled Swaps	Redmile Group, Llc Director	Director	4 872 Value: $45.4K
May 16, 2025 Buy	Common Stock	Panacea Innovation Ltd 10 Percent Owner	10% Owner	0 Value: $0
May 16, 2025 Buy	Warrants	Panacea Innovation Ltd 10 Percent Owner	10% Owner	307 900 Value: $31
May 16, 2025 Buy	Warrants	Panacea Innovation Ltd 10 Percent Owner	10% Owner	307 900 Value: $31
May 16, 2025 Buy	Common Stock	Panacea Innovation Ltd 10 Percent Owner	10% Owner	0 Value: $0
May 16, 2025 Sell	Common Stock S-Sale	Grant-huerta Yanina Chief Accounting Officer	Officer	2 218 Value: $15.0K
May 16, 2025 Sell	Common Stock S-Sale	Nguyen Anhco President And CEO	CEO / President	3 276 Value: $22.2K
May 16, 2025 Sell	Common Stock S-Sale	Nguyen Anhco President And CEO	CEO / President	3 276 Value: $22.2K
May 16, 2025 Sell	Common Stock S-Sale	Grant-huerta Yanina Chief Accounting Officer	Officer	2 218 Value: $15.0K
May 16, 2025 Buy	Common Stock A-Award	Adiumentum Capital Fund I Lp See Remarks	Director	75 572 Value: $499.5K
May 16, 2025 Buy	Warrants (right to buy) A-Award	Adiumentum Capital Fund I Lp See Remarks	Director	227 000 Value: $23

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...

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