Overview Dividends

(PRTA) Prothena - Ratings and Ratios

Exchange: NASDAQ • Country: Ireland • Currency: USD • Type: Common Stock • ISIN: IE00B91XRN20

Neurodegeneration, Antibody, Vaccine, Clinical

PRTA EPS (Earnings per Share)

EPS Growth (3Y CAGR): -2.27%
EPS Trend (3Y Correlation): -18.0%

PRTA Revenue

Revenue Growth (3Y CAGR): 47.53%
Revenue Trend (3Y Correlation): -12.1%

Description: PRTA Prothena October 26, 2025

Prothena Corporation plc (NASDAQ: PRTA) is a late-stage clinical biotech focused on antibodies that correct protein-misfolding disorders in the U.S. Its lead asset, prasinezumab-a humanized monoclonal antibody targeting α-synuclein-is in a Phase 2b trial for Parkinson’s disease and other synucleinopathies. The pipeline also includes Coramitug (Phase 2 for transthyretin amyloidosis), BMS-986446 (Phase 2 for Alzheimer’s), PRX012 (Phase 1 Alzheimer’s), PRX123 (preclinical dual Aβ-Tau vaccine), and PRX019 (Phase 1 for broader neurodegeneration). Strategic partnerships with Roche (α-synuclein) and Bristol Myers Squibb (tau, TDP-43) provide development and commercialization pathways.

Key metrics as of Q3 2024: market capitalization ≈ $650 million, cash and equivalents of $210 million giving a runway of roughly 18 months at current burn, and a 2023-24 revenue guidance of $0-$5 million (primarily from collaboration milestones). The neuro-degeneration biotech sector is projected to grow at a CAGR of ~12 % through 2030, driven by an aging population and increasing demand for disease-modifying therapies, which underpins Prothena’s market opportunity.

For a deeper, data-driven assessment of PRTA’s valuation and risk profile, you might find the analyst tools on ValueRay worth exploring.

PRTA Stock Overview

Market Cap in USD	529m
Sub-Industry	Biotechnology
IPO / Inception	2012-12-21

PRTA Stock Ratings

Growth Rating	-75.5%
Fundamental	58.7%
Dividend Rating	-
Return 12m vs S&P 500	-50.0%
Analyst Rating	4.30 of 5

PRTA Dividends

Currently no dividends paid

PRTA Growth Ratios

Growth Correlation 3m	84.4%
Growth Correlation 12m	-71.7%
Growth Correlation 5y	-46.2%
CAGR 5y	-45.34%
CAGR/Max DD 3y (Calmar Ratio)	-0.48
CAGR/Mean DD 3y (Pain Ratio)	-0.79
Sharpe Ratio 12m	0.35
Alpha	-37.58
Beta	-0.116
Volatility	66.69%
Current Volume	969.3k
Average Volume 20d	703.2k
Stop Loss	9.9 (-6.1%)
Signal	-0.44

Piotroski VR‑10 (Strict, 0-10) 2.0

Net Income (-302.9m TTM) > 0 and > 6% of Revenue (6% = 620.5k TTM)

FCFTA -0.49 (>2.0%) and ΔFCFTA -33.70pp (YES ≥ +1.0pp, WARN ≥ +0.5pp)

NWC/Revenue 3072 % (prev 248.2%; Δ 2824 pp) (YES ≤20% & Δ≤-1pp; WARN ≤25% & Δ≤0 oder ≤40% & Δ≤-3pp)

CFO/TA -0.49 (>3.0%) and CFO -196.5m > Net Income -302.9m (YES >=105%, WARN >=100%)

NO Net Debt/EBITDA fails (EBITDA <= 0)

Current Ratio 5.68 (target 1.5–3.0; WARN 1.2–<1.5 or >3.0–5.0; CFO/TA gate active)

Outstanding Shares last Quarter (53.8m) change vs 12m ago -2.21% (target <= -2.0% for YES)

Gross Margin 91.17% (prev 65.48%; Δ 25.69pp) >=18% & Δ>=+0.5pp (WARN >=15% & Δ>=0)

Asset Turnover 1.98% (prev 33.65%; Δ -31.67pp) >=50% & Δ>=+2pp (WARN >=35% & Δ>=0)

Interest Coverage Ratio -19.64 (EBITDA TTM -248.1m / Interest Expense TTM 12.7m) >= 6 (WARN >= 3)

Altman Z'' -26.60

(A) 0.80 = (Total Current Assets 385.5m - Total Current Liabilities 67.8m) / Total Assets 399.1m

(B) -3.23 = Retained Earnings (Balance) -1.29b / Total Assets 399.1m

warn (B) unusual magnitude: -3.23 — check mapping/units

(D) -17.23 = Book Value of Equity -1.29b / Total Liabilities 74.7m

Total Rating: -26.60 = (6.56 * A) + (3.26 * B) + (6.72 * C) + (1.05 * D)

ValueRay F-Score (Strict, 0-100) 58.73

1. Piotroski 2.0pt = -3.0

2. FCF Yield data missing

3. FCF Margin data missing

4. Debt/Equity 0.03 = 2.50

5. Debt/Ebitda 1.46 = 1.03

6. ROIC - WACC (= 614.3)% = 12.50

7. RoE -67.95% = -2.50

8. Rev. Trend -12.08% = -0.91

9. EPS Trend -18.02% = -0.90

What is the price of PRTA shares?

As of October 29, 2025, the stock is trading at USD 10.54 with a total of 969,343 shares traded.
Over the past week, the price has changed by +3.18%, over one month by +7.99%, over three months by +53.42% and over the past year by -40.08%.

Is Prothena a good stock to buy?

Neither. Based on ValueRay´s Fundamental Analyses, Prothena is currently (October 2025) neither a good nor a bad stock to buy. It has a ValueRay Fundamental Rating of 58.73 and therefor a neutral outlook according to the companies health.
Based on momentum, paid dividends and discounted-cash-flow analyses, the fair value of PRTA is around 8.65 USD . This means that PRTA is currently overvalued and has a potential downside of -17.93%.

Is PRTA a buy, sell or hold?

Prothena has received a consensus analysts rating of 4.30. Therefore, it is recommended to buy PRTA.

Strong Buy: 5
Buy: 3
Hold: 2
Sell: 0
Strong Sell: 0

What are the forecasts/targets for the PRTA price?

Issuer	Target	Up/Down from current
Wallstreet Target Price	13	23.3%
Analysts Target Price	13	23.3%
ValueRay Target Price	9.4	-10.9%

PRTA Fundamental Data Overview October 27, 2025

Market Cap USD = 528.6m (528.6m USD * 1.0 USD.USD)
P/E Forward = 33.8983
P/S = 51.1179
P/B = 1.6581
P/EG = 0.8
Beta = -0.116
Revenue TTM = 10.3m USD
EBIT TTM = -249.0m USD
EBITDA TTM = -248.1m USD
Long Term Debt = 9.78m USD (from capitalLeaseObligations, last quarter)
Short Term Debt = 2.85m USD (from shortTermDebt, last quarter)
Debt = 9.78m USD (from shortLongTermDebtTotal, last quarter)
Net Debt = -361.7m USD (from netDebt column, last quarter)
Enterprise Value = 167.0m USD (528.6m + Debt 9.78m - CCE 371.4m)
Interest Coverage Ratio = -19.64 (Ebit TTM -249.0m / Interest Expense TTM 12.7m)
FCF Yield = -117.8% (FCF TTM -196.7m / Enterprise Value 167.0m)
FCF Margin = -1902 % (FCF TTM -196.7m / Revenue TTM 10.3m)
Net Margin = -2929 % (Net Income TTM -302.9m / Revenue TTM 10.3m)
Gross Margin = 91.17% ((Revenue TTM 10.3m - Cost of Revenue TTM 913.0k) / Revenue TTM)
Gross Margin QoQ = 100.0% (prev 100.0%)
Tobins Q-Ratio = 0.42 (Enterprise Value 167.0m / Total Assets 399.1m)
Interest Expense / Debt = 66.96% (Interest Expense 6.55m / Debt 9.78m)
Taxrate = -55.34% (out of range, set to none) (44.8m / -81.0m)
NOPAT = unknown (EBIT/Op.Income or Taxrate missing)
Current Ratio = 5.68 (Total Current Assets 385.5m / Total Current Liabilities 67.8m)
Debt / Equity = 0.03 (Debt 9.78m / totalStockholderEquity, last quarter 324.3m)
Debt / EBITDA = 1.46 (negative EBITDA) (Net Debt -361.7m / EBITDA -248.1m)
Debt / FCF = 1.84 (negative FCF - burning cash) (Net Debt -361.7m / FCF TTM -196.7m)
Total Stockholder Equity = 445.8m (last 4 quarters mean from totalStockholderEquity)
RoA = -75.91% (Net Income -302.9m / Total Assets 399.1m)
RoE = -67.95% (Net Income TTM -302.9m / Total Stockholder Equity 445.8m)
RoCE = -54.65% (EBIT -249.0m / Capital Employed (Equity 445.8m + L.T.Debt 9.78m))
RoIC = 619.8% (negative operating profit) (EBIT -249.0m / (Assets 399.1m - Curr.Liab 67.8m - Cash 371.4m))
WACC = 5.49% (E(528.6m)/V(538.4m) * Re(5.59%) + (debt cost/tax rate unavailable))
Discount Rate = 5.59% (= CAPM, Blume Beta Adj.) -> floored to rf + 0.7*ERP = 8.05%
Shares Correlation 3-Years: 100.0 | Cagr: 0.15%
Fair Price DCF = unknown (Cash Flow -196.7m)
EPS Correlation: -18.02 | EPS CAGR: -2.27% | SUE: 0.66 | # QB: 0
Revenue Correlation: -12.08 | Revenue CAGR: 47.53% | SUE: -0.02 | # QB: 0

Additional Sources for PRTA Stock

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