Renaissance Technologies LLC Has $5.91 Million Stock Position in Prothena Corporation plc $PRTA

Posted by George Bondi on Aug 6th, 2026

Renaissance Technologies LLC increased its stake in shares of Prothena Corporation plc (NASDAQ:PRTA – Free Report) by 39.5% during the first quarter, according to its most recent disclosure with the Securities and Exchange Commission. The firm owned 607,515 shares of the biotechnology company’s stock after acquiring an additional 172,000 shares during the quarter. Renaissance Technologies LLC owned about 1.16% of Prothena worth $5,905,000 at the end of the most recent reporting period.

A number of other hedge funds have also recently bought and sold shares of PRTA. Intech Investment Management LLC raised its holdings in Prothena by 5.5% in the 3rd quarter. Intech Investment Management LLC now owns 19,388 shares of the biotechnology company’s stock valued at $189,000 after acquiring an additional 1,014 shares in the last quarter. Brooklyn Investment Group grew its holdings in shares of Prothena by 13.1% during the 3rd quarter. Brooklyn Investment Group now owns 12,569 shares of the biotechnology company’s stock worth $123,000 after purchasing an additional 1,456 shares in the last quarter. Deutsche Bank AG increased its position in shares of Prothena by 5.1% during the fourth quarter. Deutsche Bank AG now owns 35,482 shares of the biotechnology company’s stock valued at $339,000 after purchasing an additional 1,709 shares during the period. Price T Rowe Associates Inc. MD increased its position in shares of Prothena by 3.8% during the fourth quarter. Price T Rowe Associates Inc. MD now owns 81,515 shares of the biotechnology company’s stock valued at $779,000 after purchasing an additional 2,968 shares during the period. Finally, Virtus Investment Advisers LLC raised its stake in shares of Prothena by 14.4% in the 4th quarter. Virtus Investment Advisers LLC now owns 25,679 shares of the biotechnology company’s stock valued at $245,000 after buying an additional 3,236 shares in the last quarter. 97.08% of the stock is owned by institutional investors.

Insider Buying and Selling at Prothena

In other Prothena news, insider Anne Evans Kingston sold 7,662 shares of the business’s stock in a transaction on Wednesday, July 29th. The stock was sold at an average price of $8.47, for a total value of $64,897.14. Following the transaction, the insider owned 55,782 shares of the company’s stock, valued at approximately $472,473.54. The trade was a 12.08% decrease in their ownership of the stock. The transaction was disclosed in a document filed with the Securities & Exchange Commission, which can be accessed through this hyperlink. Also, General Counsel Michael John Isaacs sold 8,386 shares of the firm’s stock in a transaction on Wednesday, July 29th. The shares were sold at an average price of $8.47, for a total value of $71,029.42. Following the completion of the sale, the general counsel owned 35,745 shares of the company’s stock, valued at approximately $302,760.15. This trade represents a 19.00% decrease in their ownership of the stock. The disclosure for this sale is available in the SEC filing. In the last quarter, insiders acquired 345,000 shares of company stock worth $3,097,250. 10.40% of the stock is currently owned by insiders.

Wall Street Analyst Weigh In

A number of analysts recently weighed in on PRTA shares. Citizens Jmp upped their target price on shares of Prothena from $19.00 to $20.00 and gave the company a “market outperform” rating in a research note on Friday, May 8th. HC Wainwright reaffirmed a “buy” rating and set a $30.00 price objective on shares of Prothena in a report on Friday, July 24th. Citigroup reissued an “outperform” rating on shares of Prothena in a report on Friday, May 8th. Weiss Ratings raised Prothena from a “sell (e+)” rating to a “sell (d-)” rating in a research note on Tuesday, July 28th. Finally, Wall Street Zen cut Prothena from a “buy” rating to a “hold” rating in a research report on Saturday, July 25th. One equities research analyst has rated the stock with a Strong Buy rating, five have given a Buy rating, one has assigned a Hold rating and one has assigned a Sell rating to the company. According to MarketBeat, Prothena currently has an average rating of “Moderate Buy” and an average target price of $23.75.

Read Our Latest Stock Analysis on PRTA

Prothena Stock Performance

NASDAQ PRTA opened at $8.49 on Thursday. Prothena Corporation plc has a 1-year low of $7.28 and a 1-year high of $11.80. The company has a 50 day moving average of $8.96 and a 200-day moving average of $9.41. The firm has a market cap of $444.45 million, a price-to-earnings ratio of -3.01, a PEG ratio of 1.36 and a beta of -0.30.

Prothena (NASDAQ:PRTA – Get Free Report) last announced its earnings results on Thursday, May 7th. The biotechnology company reported $0.60 EPS for the quarter, topping the consensus estimate of ($0.31) by $0.91. The business had revenue of $51.08 million for the quarter, compared to the consensus estimate of $0.81 million. Prothena had a negative return on equity of 43.44% and a negative net margin of 260.92%. On average, analysts forecast that Prothena Corporation plc will post 0.18 earnings per share for the current year.

Prothena Company Profile

(Free Report)

Prothena Corporation plc is a clinical-stage biotechnology company dedicated to the discovery and development of novel therapies for neurodegenerative and rare diseases driven by misfolded proteins. The company’s research focuses on immunotherapies and small molecules designed to target and clear disease-causing protein aggregates. Prothena leverages proprietary protein engineering and antibody discovery platforms to advance candidates through preclinical and clinical stages.

The company’s most advanced program is an antibody targeting aggregated alpha-synuclein for the potential treatment of Parkinson’s disease, currently in mid-stage clinical trials.