Prothena PLC - (PRTA) closed at $8.78 on November 9, 2026, up 10.1% from the previous close, on volume of 715,461 shares (30-day average 511,898).
Data as of November 9, 2026.
RBC Capital Sticks to Its Hold Rating for Prothena (PRTA)
TipRanks (Fri, 6-Nov 9:42 AM ET)
Piper Sandler Reaffirms Their Buy Rating on Prothena (PRTA)
TipRanks (Fri, 6-Nov 9:24 AM ET)
Bank of America Securities Sticks to Their Sell Rating for Prothena (PRTA)
TipRanks (Fri, 6-Nov 9:24 AM ET)
Prothena Reports Third Quarter 2026 Financial Results and Business Highlights
Business Wire (Thu, 5-Nov 4:05 PM ET)
Prothena to Report Third Quarter 2026 Financial Results on November 5
Business Wire (Thu, 29-Oct 4:05 PM ET)
Prothena to Participate in the H.C. Wainwright 28th Annual Global Investment Conference
Business Wire (Wed, 9-Sep 4:05 PM ET)
Prothena Corp PLC is a late-stage clinical biotechnology company that focuses on protein dysregulation and a pipeline of investigational therapeutics with the potential to change the course of devastating neurodegenerative and rare and peripheral amyloid diseases. Prothena is developing and applying its proprietary CYTOPE technology to target a broad spectrum of intracellular disease pathways in the brain and periphery. The company's pipeline includes both wholly-owned and partnered programs like Prasinezumab, Coramitug (PRX004), BMS-986446 (PRX005), PRX019, TDP-43 CYTOPE, and PRX012-TfR, being developed for the potential treatment of Parkinson's disease, ATTR amyloidosis with cardiomyopathy, Alzheimer's disease, Amyotrophic lateral sclerosis (ALS), and other neurodegenerative diseases.
Prothena PLC - trades on the NASDAQ stock market under the symbol PRTA.
As of November 10, 2026, PRTA stock price declined to $8.53 with 13,712 million shares trading.
PRTA has a beta of 0.74, meaning it tends to be less sensitive to market movements. PRTA has a correlation of 0.04 to the broad based SPY ETF.
PRTA has a market cap of $446.57 million. This is considered a Small Cap stock.
Last quarter Prothena PLC - reported $620,000 in Revenue and -$.32 earnings per share. This fell short of revenue expectation by $-6 million and met earnings estimates .
In the last 3 years, PRTA traded as high as $41.55 and as low as $4.32.
The top ETF exchange traded funds that PRTA belongs to (by Net Assets): IWM, XBI, VXF, DFAS, IBB.
PRTA has underperformed the market in the last year with a return of -19.2%, while SPY returned +12.7%. This shows that you would have done better investing in the overall market (through SPY) over the last year than in PRTA shares. However, PRTA has outperformed the market in the last 3 month and 2 week periods, returning -2.6% and +1.5%, while SPY returned -2.9% and -2.2%, respectively. This indicates PRTA has been having a stronger performance recently.
PRTA support price is $8.45 and resistance is $9.10 (based on 1 day standard deviation move). This means that using the most recent 20 day stock volatility and applying a one standard deviation move around the stock's closing price, stastically there is a 67% probability that PRTA shares will trade within this expected range on the day.