EcoR1 Capital LLC Cuts Position in Atara Biotherapeutics, Inc. $ATRA

Posted by Stanley Muller on Jul 28th, 2026

EcoR1 Capital LLC trimmed its stake in Atara Biotherapeutics, Inc. (NASDAQ:ATRA – Free Report) by 82.6% in the 1st quarter, HoldingsChannel reports. The fund owned 99,593 shares of the biotechnology company’s stock after selling 473,590 shares during the quarter. Atara Biotherapeutics comprises 0.0% of EcoR1 Capital LLC’s investment portfolio, making the stock its 28th largest position. EcoR1 Capital LLC’s holdings in Atara Biotherapeutics were worth $471,000 as of its most recent SEC filing.

Several other institutional investors and hedge funds also recently added to or reduced their stakes in the stock. Raymond James Financial Inc. bought a new stake in shares of Atara Biotherapeutics in the 2nd quarter valued at about $31,000. Dimensional Fund Advisors LP purchased a new position in Atara Biotherapeutics in the fourth quarter worth $181,000. Walleye Capital LLC acquired a new position in shares of Atara Biotherapeutics during the fourth quarter worth $220,000. Quadrature Capital Ltd lifted its holdings in shares of Atara Biotherapeutics by 22.8% during the 4th quarter. Quadrature Capital Ltd now owns 20,321 shares of the biotechnology company’s stock valued at $368,000 after purchasing an additional 3,779 shares during the last quarter. Finally, Renaissance Technologies LLC lifted its holdings in shares of Atara Biotherapeutics by 58.6% during the 4th quarter. Renaissance Technologies LLC now owns 30,040 shares of the biotechnology company’s stock valued at $543,000 after purchasing an additional 11,104 shares during the last quarter. Hedge funds and other institutional investors own 70.90% of the company’s stock.

Analysts Set New Price Targets

Several research analysts recently weighed in on the company. Canaccord Genuity Group set a $13.00 target price on Atara Biotherapeutics and gave the stock a “buy” rating in a research note on Friday, May 8th. Weiss Ratings upgraded Atara Biotherapeutics from a “sell (e+)” rating to a “sell (d-)” rating in a research note on Wednesday, July 15th. Freedom Capital upgraded Atara Biotherapeutics from a “strong sell” rating to a “hold” rating in a research note on Monday, May 18th. Finally, Wall Street Zen upgraded shares of Atara Biotherapeutics from a “sell” rating to a “hold” rating in a report on Saturday, June 27th. One research analyst has rated the stock with a Buy rating, one has issued a Hold rating and one has issued a Sell rating to the stock. According to data from MarketBeat.com, the company has an average rating of “Hold” and a consensus price target of $9.50.

Check Out Our Latest Stock Analysis on ATRA

Insider Transactions at Atara Biotherapeutics

In related news, major shareholder Innovation Ltd Panacea sold 313,446 shares of Atara Biotherapeutics stock in a transaction dated Thursday, May 7th. The stock was sold at an average price of $10.10, for a total transaction of $3,165,804.60. Following the completion of the sale, the insider owned 1,011,000 shares of the company’s stock, valued at $10,211,100. The trade was a 23.67% decrease in their ownership of the stock. The transaction was disclosed in a document filed with the SEC, which is available through this hyperlink. Also, CEO Anhco Nguyen sold 5,241 shares of the company’s stock in a transaction that occurred on Monday, May 18th. The shares were sold at an average price of $9.13, for a total value of $47,850.33. Following the completion of the sale, the chief executive officer owned 137,837 shares in the company, valued at approximately $1,258,451.81. This represents a 3.66% decrease in their position. The disclosure for this sale is available in the SEC filing. The sale was made to cover tax withholding obligations related to the vesting of equity awards. Insiders have sold 321,101 shares of company stock valued at $3,235,695 in the last ninety days. Corporate insiders own 41.20% of the company’s stock.

Atara Biotherapeutics Price Performance

NASDAQ ATRA opened at $7.71 on Tuesday. The stock’s fifty day moving average price is $9.83 and its 200 day moving average price is $7.17. Atara Biotherapeutics, Inc. has a 1 year low of $3.92 and a 1 year high of $19.15. The company has a market cap of $69.47 million, a price-to-earnings ratio of -11.51 and a beta of 0.08.

Atara Biotherapeutics (NASDAQ:ATRA – Get Free Report) last issued its quarterly earnings results on Tuesday, May 12th. The biotechnology company reported ($0.29) EPS for the quarter, topping analysts’ consensus estimates of ($0.33) by $0.04. The company had revenue of $0.52 million during the quarter, compared to analysts’ expectations of $2.90 million. Atara Biotherapeutics had a negative return on equity of 79.12% and a negative net margin of 40.91%. Research analysts expect that Atara Biotherapeutics, Inc. will post -0.16 earnings per share for the current year.

About Atara Biotherapeutics

(Free Report)

Atara Biotherapeutics, Inc is a biotechnology company focused on the discovery, development and commercialization of novel T-cell immunotherapies to transform the treatment of cancer and autoimmune disease. Headquartered in South San Francisco, California, Atara leverages its proprietary off-the-shelf allogeneic Epstein-Barr virus (EBV)-directed T-cell platform to generate engineered cell therapies designed to target EBV-driven malignancies and immune-mediated disorders.

The company’s lead product candidate, tabelecleucel, is an off-the-shelf, EBV-specific T-cell therapy in clinical development for the treatment of EBV-positive post-transplant lymphoproliferative disease (PTLD) and other EBV-associated cancers.