NASDAQ: PRTA
Prothena Corp Public Ltd Co Stock

$9.61+0.26 (+2.78%)
Updated Sep 1, 2026
PRTA Price
$9.61
Fair Value Price
$3.51
Market Cap
$493.35M
52 Week Low
$7.73
52 Week High
$11.80
P/E
-11.58x
P/B
1.72x
P/S
9.36x
PEG
N/A
Dividend Yield
N/A
Revenue
$54.53M
Earnings
-$43.99M
Gross Margin
100%
Operating Margin
-81.33%
Profit Margin
-80.7%
Debt to Equity
0.06
Operating Cash Flow
-$60M
Beta
1.42
Next Earnings
N/A
Ex-Dividend
N/A
Next Dividend
N/A

PRTA Overview

Prothena Corporation plc, a late-stage clinical biotechnology company, focuses on discovery and development of novel therapies to treat diseases caused by protein dysregulation. Its product pipeline includes Prasinezumab, an investigational humanized monoclonal antibody which is in Phase 3 clinical trial for the treatment of parkinson's disease and other synucleinopathies. The company also develops Coramitug, an investigational antibody, which is in Phase 3 clinical trial for the treatment of transthyretin amyloidosis; BMS-986446, an anti-tau antibody which is in Phase 2 clinical trial to treat Alzheimer's disease; PRX019, an investigational antibody which is in Phase 1 clinical trial for the treatment of neurodegenerative diseases; and PRX123, a Dual Aß-Tau Vaccine, which is in preclinical trial for treating Alzheimer's disease. In addition, it develops discovery- and late-preclinical-stage programs include TDP-43 CYTOPE for the treatment of amyotrophic lateral sclerosis; PRX012, a next-generation anti-Aß antibody which is in phase 1 clinical trial to treat Alzheimer's disease; and PRX012-TfR, a preclinical program for the treatment of Alzheimer's disease. It has a license, development, and commercialization agreement with F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. to develop and commercialize antibodies that target a-synuclein, including prasinezumab; and master collaboration agreement with Bristol Myers Squibb to develop and commercialize antibodies targeting tau, TDP-43. Prothena Corporation plc was incorporated in 2012 and is based in Dublin, Ireland.

Zen Rating

Our proven quant model uses 115 proprietary factors, including AI, to determine PRTA's potential to beat the market

CHold
  • Stocks with a Zen Rating of Hold (C) had an average return of +5.11% per year. Learn More

Zen Rating Component Grades

C
Zen Rating uses advanced AI algorithms that detect subtle patterns in market data; it anticipates future trends that point to superior stock price results.

Industry: Biotech

Industry Rating
F
PRTA
Ranked
#117 of 463

Top Ranked Stocks in Industry

Name / TickerPriceZen Rating
$9.35A
$113.38A
$6.86A
View Top Biotech Stocks

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PRTA News

Overview

Due Diligence Score

Industry Average (24)
You've viewed Due Diligence Score for 10/10 free stocks. Upgrade to Premium to see how PRTA scored across 33 valuation, financial, forecast, performance, and dividend due diligence checks.

Due Diligence Checks

PRTA ($9.61) is overvalued by 174.08% relative to our estimate of its Fair Value price of $3.51 based on Discounted Cash Flow (DCF) modelling
Below Fair Value Valuation
PRTA ($9.61) is not significantly undervalued (174.08%) relative to our estimate of its Fair Value price of $3.51 based on Discounted Cash Flow (DCF) modelling, when including a healthy margin of safety
Significantly Below Fair Value Valuation
PRTA is unprofitable, so we... subscribe to Premium to read more.
Below Benjamin Graham Formula Value Valuation
There are 30 more PRTA due diligence checks available for Premium users.

Valuation

PRTA fair value

Fair Value of PRTA stock based on Discounted Cash Flow (DCF)

Price
$9.61
Fair Value
$3.51
Overvalued by
174.08%
PRTA ($9.61) is overvalued by... subscribe to Premium to read more.
Below Fair Value Valuation
PRTA ($9.61) is not significantly... subscribe to Premium to read more.
Significantly Below Fair Value Valuation
PRTA is unprofitable, so we... subscribe to Premium to read more.
Below Benjamin Graham Formula Value Valuation

PRTA price to earnings (PE)

For valuing profitable companies with steady earnings

Company
-11.58x
Industry
15.43x
Market
40.12x

PRTA price to book (PB)

For valuing companies that are loss-making or have lots of physical asset

Company
1.72x
Industry
5.5x
PRTA is good value based... subscribe to Premium to read more.
P/B vs Industry Valuation

PRTA's financial health

Profit margin

Revenue
$1.0M
Net Income
-$18.6M
Profit Margin
-1,839.9%
PRTA's cash burn is expected... subscribe to Premium to read more.
Interest Coverage Financials
PRTA's profit margin has increased... subscribe to Premium to read more.
Profit Margin Growth Financials

Assets to liabilities

Assets
$302.6M
Liabilities
$15.7M
Debt to equity
0.06
PRTA's short-term assets ($292.01M) exceed... subscribe to Premium to read more.
Short-term Liabilities Financials
PRTA's short-term assets ($292.01M) exceed... subscribe to Premium to read more.
Long-term Liabilities Financials
PRTA's debt relative to shareholder... subscribe to Premium to read more.
Shrinking Debt Financials
PRTA's debt to equity ratio... subscribe to Premium to read more.
Healthy Debt to Equity Financials

Cash flow

Operating
-$25.0M
Investing
-$652.0k
Financing
-$15.6M
PRTA's cash and short-term investments... subscribe to Premium to read more.
Debt Coverage Financials

PRTA vs Biotech Stocks

TickerZen RatingMarket Cap1d %P/EP/B
PRTAC$493.35M+2.78%-11.58x1.72x
ENTXD$502.11M-1.69%-8.29x69.10x
PBYIA$482.65M+2.63%17.31x3.48x
CCCCC$476.11M+4.31%-4.25x1.93x
RLMDC$475.75M+2.29%-4.85x2.30x

Prothena Public Co Stock FAQ

What is Prothena Public Co's quote symbol?

(NASDAQ: PRTA) Prothena Public Co trades on the NASDAQ under the ticker symbol PRTA. Prothena Public Co stock quotes can also be displayed as NASDAQ: PRTA.

If you're new to stock investing, here's how to buy Prothena Public Co stock.

What is the 52 week high and low for Prothena Public Co (NASDAQ: PRTA)?

(NASDAQ: PRTA) Prothena Public Co's 52-week high was $11.80, and its 52-week low was $7.73. It is currently -18.56% from its 52-week high and 24.32% from its 52-week low.

How much is Prothena Public Co stock worth today?

(NASDAQ: PRTA) Prothena Public Co currently has 51,336,974 outstanding shares. With Prothena Public Co stock trading at $9.61 per share, the total value of Prothena Public Co stock (market capitalization) is $493.35M.

Prothena Public Co stock was originally listed at a price of $7.20 in Dec 21, 2012. If you had invested in Prothena Public Co stock at $7.20, your return over the last 13 years would have been 33.47%, for an annualized return of 2.25% (not including any dividends or dividend reinvestments).

How much is Prothena Public Co's stock price per share?

(NASDAQ: PRTA) Prothena Public Co stock price per share is $9.61 today (as of Sep 1, 2026).

What is Prothena Public Co's Market Cap?

(NASDAQ: PRTA) Prothena Public Co's market cap is $493.35M, as of Sep 2, 2026.

Market cap (market capitalization) is the total market value of a publicly traded company's outstanding shares.

Prothena Public Co's market cap is calculated by multiplying PRTA's current stock price of $9.61 by PRTA's total outstanding shares of 51,336,974.
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