Prothena (PRTA) News Today $4.59 -0.11 (-2.34%) Closing price 05/30/2025 04:00 PM EasternExtended Trading$4.66 +0.07 (+1.42%) As of 05/30/2025 07:46 PM Eastern Extended trading is trading that happens on electronic markets outside of regular trading hours. This is a fair market value extended hours price provided by Polygon.io. Learn more. Add Compare Share Share Headlines Stock AnalysisAnalyst ForecastsChartCompetitorsEarningsFinancialsHeadlinesInsider TradesOptions ChainOwnershipSEC FilingsShort InterestTrendsBuy This Stock Why is Prothena Down Today?Prothena Co. plc (NASDAQ:PRTA) shares are trading lower after analysts cut earnings estimates and ratings amid clinical trial setbacks. The moves follow the May 23 announcement that the Phase 3 AFFIRM-AL trial for Birtamimab in AL Amyloidosis patients failed to meet its primary endpoint, prompting multiple price target reductions. H.C. Wainwright maintains a Buy rating on PRTA. Chardan Capital retains its Buy rating with an $18 price objective. Piper Sandler cuts its price target to $81. Oppenheimer downgrades the stock to Perform from Outperform. Bank of America lowers its rating to Underperform and sets a $4 target. Chardan Capital cuts FY2025 EPS estimate to ($3.80); HC Wainwright cuts FY2027 EPS to ($5.44). Multiple analysts (BofA Securities, Piper Sandler, Oppenheimer) issue pessimistic forecasts following the trial failure. Posted 1+ days agoAI Generated. May Contain Errors. PRTA Latest News All Sources Trusted Sources MarketBeat Benzinga Bloomberg GlobeNewswire GuruFocus MarketWatch Motley Fool NASDAQ PR Newswire Reuters Seeking Alpha TalkMarkets The Street TipRanks The Wall Street Journal Wall Street Zen Yahoo Finance Source Sentiment refers to the positivity or negativity of each headline according to our language processing algorithm. Sentiment All Sentiments Very Positive Positive Neutral Negative Very Negative Most Recent June 2025 May 2025 April 2025 March 2025 February 2025 January 2025 December 2024 November 2024 October 2024 September 2024 August 2024 July 2024 June 2024 May 2024 April 2024 March 2024 February 2024 January 2024 December 2023 November 2023 October 2023 September 2023 August 2023 July 2023 June 2023 May 2023 April 2023 March 2023 February 2023 January 2023 December 2022 November 2022 October 2022 September 2022 August 2022 July 2022 June 2022 Time Period Prothena Co. plc (NASDAQ:PRTA) Given Consensus Recommendation of "Hold" by BrokeragesProthena Co. plc (NASDAQ:PRTA - Get Free Report) has been assigned a consensus rating of "Hold" from the nine brokerages that are currently covering the stock, Marketbeat reports. One investment analyst has rated the stock with a sell rating, four have issued a hold rating and four have issued aJune 1 at 3:25 AM | marketbeat.comFY2025 EPS Estimates for Prothena Cut by Chardan CapitalProthena Co. plc (NASDAQ:PRTA - Free Report) - Equities researchers at Chardan Capital reduced their FY2025 earnings per share (EPS) estimates for Prothena in a research note issued on Tuesday, May 27th. Chardan Capital analyst R. Li now anticipates that the biotechnology company will post earninMay 31 at 6:27 AM | marketbeat.comHC Wainwright Has Weak Outlook for Prothena FY2027 EarningsMay 31 at 2:45 AM | americanbankingnews.comPiper Sandler Reduces Prothena (PRTA) Price Target to $81 from $110 Following AFFIRM-AL Trial DiscontinuationMay 30 at 5:42 PM | msn.comChardan Lowers Prothena (PRTA) Price Target Following AFFIRM-AL Trial FailureMay 30 at 5:42 PM | msn.comH.C. Wainwright Maintains Buy Rating on Prothena Corporation (NASDAQ:PRTA), Cuts PTMay 30 at 11:42 AM | insidermonkey.comFY2027 EPS Estimates for Prothena Decreased by HC WainwrightProthena Co. plc (NASDAQ:PRTA - Free Report) - HC Wainwright dropped their FY2027 earnings per share estimates for shares of Prothena in a note issued to investors on Tuesday, May 27th. HC Wainwright analyst A. Fein now forecasts that the biotechnology company will earn ($5.44) per share for theMay 30 at 8:42 AM | marketbeat.comWellington Management Group LLP Increases Position in Prothena Co. plc (NASDAQ:PRTA)Wellington Management Group LLP increased its stake in Prothena Co. plc (NASDAQ:PRTA - Free Report) by 22.8% in the fourth quarter, according to its most recent 13F filing with the Securities & Exchange Commission. The institutional investor owned 5,130,876 shares of the biotechnology company'May 30 at 5:53 AM | marketbeat.comProthena (NASDAQ:PRTA) Given Underperform Rating at Bank of AmericaMay 30 at 4:07 AM | americanbankingnews.comOppenheimer Downgrades Prothena Corporation (NASDAQ:PRTA) to Perform from OutperformMay 30 at 1:47 AM | finance.yahoo.comB of A Securities Downgrades Prothena (PRTA)May 29 at 9:48 AM | msn.comProthena (NASDAQ:PRTA) Lowered to Underperform Rating by Bank of AmericaBank of America lowered shares of Prothena from a "neutral" rating to an "underperform" rating and set a $4.00 price target on the stock. in a research report on Wednesday.May 29 at 8:52 AM | marketbeat.comProthena (NASDAQ:PRTA) Price Target Cut to $81.00 by Analysts at Piper SandlerMay 29 at 2:38 AM | americanbankingnews.comProthena (NASDAQ:PRTA) Stock Rating Lowered by OppenheimerMay 29 at 2:03 AM | americanbankingnews.comChardan Capital Issues Pessimistic Forecast for Prothena (NASDAQ:PRTA) Stock PriceMay 29 at 1:15 AM | americanbankingnews.comJefferies Downgrades Prothena Corporation (PRTA) After Negative Trial ResultsMay 29 at 12:57 AM | finance.yahoo.comOppenheimer Downgrades Prothena Corporation (NASDAQ:PRTA) to Perform from OutperformMay 28, 2025 | insidermonkey.comPiper Sandler Issues Pessimistic Forecast for Prothena (NASDAQ:PRTA) Stock PricePiper Sandler cut their price objective on Prothena from $110.00 to $81.00 and set an "overweight" rating for the company in a research report on Tuesday.May 28, 2025 | marketbeat.comProthena Target of Unusually High Options Trading (NASDAQ:PRTA)Prothena Co. plc (NASDAQ:PRTA - Get Free Report) saw unusually large options trading activity on Tuesday. Traders purchased 8,185 put options on the stock. This represents an increase of approximately 1,210% compared to the average volume of 625 put options.May 28, 2025 | marketbeat.comJMP Securities Cuts Prothena (NASDAQ:PRTA) Price Target to $29.00JMP Securities decreased their price objective on shares of Prothena from $78.00 to $29.00 and set a "market outperform" rating on the stock in a research report on Tuesday.May 28, 2025 | marketbeat.comProthena (NASDAQ:PRTA) Downgraded by Cantor Fitzgerald to NeutralCantor Fitzgerald downgraded Prothena from an "overweight" rating to a "neutral" rating in a research note on Tuesday.May 28, 2025 | marketbeat.comProthena (NASDAQ:PRTA) Downgraded by Jefferies Financial Group to HoldJefferies Financial Group lowered Prothena from a "buy" rating to a "hold" rating and set a $6.00 target price on the stock. in a research report on Tuesday.May 28, 2025 | marketbeat.comProthena (NASDAQ:PRTA) Cut to Market Perform at OppenheimerOppenheimer downgraded shares of Prothena from an "outperform" rating to a "market perform" rating in a research report on Tuesday.May 28, 2025 | marketbeat.comChardan Capital Lowers Prothena (NASDAQ:PRTA) Price Target to $18.00Chardan Capital decreased their target price on Prothena from $40.00 to $18.00 and set a "buy" rating on the stock in a research report on Tuesday.May 28, 2025 | marketbeat.comHC Wainwright Issues Pessimistic Forecast for Prothena (NASDAQ:PRTA) Stock PriceHC Wainwright lowered their target price on shares of Prothena from $30.00 to $14.00 and set a "buy" rating for the company in a research note on Tuesday.May 28, 2025 | marketbeat.comAnalysts Offer Insights on Healthcare Companies: Prothena (PRTA) and Bristol-Myers Squibb (BMY)May 28, 2025 | theglobeandmail.comJMP Securities Lowers Prothena (NASDAQ:PRTA) Price Target to $29.00May 28, 2025 | americanbankingnews.comProthena (NASDAQ:PRTA) Downgraded to Neutral Rating by Cantor FitzgeraldMay 28, 2025 | americanbankingnews.comProthena (NASDAQ:PRTA) Downgraded to Hold Rating by Jefferies Financial GroupMay 28, 2025 | americanbankingnews.comHC Wainwright Lowers Prothena (NASDAQ:PRTA) Price Target to $14.00May 28, 2025 | americanbankingnews.comPeninsula biotech Prothena falters — again — and layoffs are on the wayMay 27, 2025 | bizjournals.comProthena: Despite Phase 3 Trial Failure, Other Neurodegenerative Programs In PlaceMay 27, 2025 | seekingalpha.comProthena hits 52-week low amid downgrades after late-stage trial setbackMay 27, 2025 | msn.comJefferies Downgrades Prothena Corporation (PRTA) After Negative Trial ResultsMay 27, 2025 | insidermonkey.comWhy Is Prothena Stock Trading Lower On Tuesday?May 27, 2025 | benzinga.comDeutsche Bank AG Purchases 63,512 Shares of Prothena Co. plc (NASDAQ:PRTA)Deutsche Bank AG raised its position in shares of Prothena Co. plc (NASDAQ:PRTA - Free Report) by 195.7% in the fourth quarter, according to its most recent Form 13F filing with the Securities and Exchange Commission (SEC). The firm owned 95,970 shares of the biotechnology company's stock after acqMay 26, 2025 | marketbeat.comProthena Announces Phase 3 AFFIRM-AL Clinical Trial for Birtamimab in Patients with AL Amyloidosis Did Not Meet Primary EndpointMay 23, 2025 | businesswire.comBNP Paribas Financial Markets Purchases 41,541 Shares of Prothena Co. plc (NASDAQ:PRTA)BNP Paribas Financial Markets lifted its holdings in Prothena Co. plc (NASDAQ:PRTA - Free Report) by 74.4% during the 4th quarter, according to its most recent filing with the Securities & Exchange Commission. The firm owned 97,383 shares of the biotechnology company's stock after purchasing anMay 22, 2025 | marketbeat.comBalyasny Asset Management L.P. Makes New $527,000 Investment in Prothena Co. plc (NASDAQ:PRTA)Balyasny Asset Management L.P. acquired a new position in shares of Prothena Co. plc (NASDAQ:PRTA - Free Report) during the 4th quarter, according to the company in its most recent disclosure with the Securities & Exchange Commission. The firm acquired 38,021 shares of the biotechnology companyMay 18, 2025 | marketbeat.comCantor Fitzgerald Upgrades Prothena (NASDAQ:PRTA) to "Strong-Buy"Cantor Fitzgerald upgraded Prothena to a "strong-buy" rating in a research report on Tuesday.May 17, 2025 | marketbeat.comProsight Management LP Sells 65,345 Shares of Prothena Co. plc (NASDAQ:PRTA)Prosight Management LP lessened its holdings in shares of Prothena Co. plc (NASDAQ:PRTA - Free Report) by 13.5% in the fourth quarter, according to its most recent disclosure with the Securities & Exchange Commission. The firm owned 418,122 shares of the biotechnology company's stock after sellMay 17, 2025 | marketbeat.comProthena Shareholders Approve Key Amendments at AGMMay 16, 2025 | tipranks.comCantor Fitzgerald Expects Increased Earnings for ProthenaProthena Co. plc (NASDAQ:PRTA - Free Report) - Equities researchers at Cantor Fitzgerald upped their FY2025 EPS estimates for shares of Prothena in a research note issued on Monday, May 12th. Cantor Fitzgerald analyst C. Duncan now forecasts that the biotechnology company will post earnings of ($May 16, 2025 | marketbeat.comProthena (NASDAQ:PRTA) Issues Quarterly Earnings ResultsProthena (NASDAQ:PRTA - Get Free Report) announced its quarterly earnings data on Thursday. The biotechnology company reported ($1.12) earnings per share for the quarter, missing analysts' consensus estimates of ($0.92) by ($0.20). Prothena had a negative net margin of 90.50% and a negative return on equity of 22.67%. The business had revenue of $2.83 million during the quarter, compared to analysts' expectations of $8.18 million. During the same period in the prior year, the firm posted ($1.34) EPS. Prothena's revenue for the quarter was up 5500.0% compared to the same quarter last year.May 12, 2025 | marketbeat.comProthena (NASDAQ:PRTA) Receives "Buy" Rating from Chardan CapitalChardan Capital restated a "buy" rating and set a $40.00 target price on shares of Prothena in a report on Friday.May 11, 2025 | marketbeat.comProthena Corporation plc: Prothena Reports First Quarter 2025 Financial Results and Business HighlightsMay 9, 2025 | finanznachrichten.deProthena Corp (PRTA) Sees Price Target Reduction by HC Wainwright & Co. | PRTA Stock NewsMay 9, 2025 | gurufocus.comProthena Corp (PRTA) Sees Price Target Adjusted by JMP Securities | PRTA Stock NewsMay 9, 2025 | gurufocus.comIs Prothena Corporation plc (PRTA) the Low Risk High Reward Stock Set to Triple by 2030?May 9, 2025 | msn.comProthena Reports First Quarter 2025 Financial Results and Business HighlightsMay 9, 2025 | finance.yahoo.com Get Prothena News Delivered to You Automatically Sign up to receive the latest news and ratings for PRTA and its competitors with MarketBeat's FREE daily newsletter. Email Address PRTA Media Mentions By Week PRTA Media Sentiment Learn about the media sentiment score. Each headline receives a score ranging from 2 (good news) to -2 (bad news). Our company news sentiment scores track the average news sentiment of articles about each company over the most recent 7 days in order to identify companies that are receiving positive press. PRTA News Sentiment▼-0.330.88▲Average Medical News Sentiment PRTA News Coverage Learn about the media coverage comparison. We track news headlines from hundreds of news outlets and tag them by company. This chart compares the number of articles about this company in the last seven days compared with the average number of articles about this company on a typical week. PRTA Articles This Week▼535▲PRTA Articles Average Week Get Prothena News Delivered to You Automatically Sign up to receive the latest news and ratings for PRTA and its competitors with MarketBeat's FREE daily newsletter. 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