Overview Dividends

(PRTA) Prothena - Ratings and Ratios

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

Neurodegeneration, Antibody, Vaccine, Clinical

Biotechnology
Market Cap in USD: 522m
IPO / Inception: 2012-12-21
Return 12m vs S&P 500: -47.8%

EPS (Earnings per Share)

EPS (Earnings per Share) of PRTA over the last years for every Quarter: "2020-12": -0.77, "2021-03": -0.91, "2021-06": 0.58, "2021-09": 2.13, "2021-12": -0.71, "2022-03": -0.78, "2022-06": -0.88, "2022-09": -0.97, "2022-12": 0.12, "2023-03": -0.89, "2023-06": -1.03, "2023-09": 0.38, "2023-12": -1.26, "2024-03": -1.34, "2024-06": 1.22, "2024-09": -1.1, "2024-12": -1.08, "2025-03": -1.12, "2025-06": -1.73, "2025-09": -0.67,
EPS CAGR: 0.94%
EPS Trend: -11.6%
Last SUE: -0.16
Qual. Beats: 0

Revenue

Revenue of PRTA over the last years for every Quarter: 2020-12: 0.36, 2021-03: 0.16, 2021-06: 60.071, 2021-09: 139.174, 2021-12: 1.172, 2022-03: 1.153, 2022-06: 1.312, 2022-09: 1.517, 2022-12: 49.923, 2023-03: 2.169, 2023-06: 4.019, 2023-09: 84.866, 2023-12: 0.316, 2024-03: 0.05, 2024-06: 132.014, 2024-09: 0.97, 2024-12: 2.123, 2025-03: 2.828, 2025-06: 4.42, 2025-09: 2.415,
Rev. CAGR: 21.26%
Rev. Trend: 4.9%
Last SUE: -0.10
Qual. Beats: 0

Dividends

Currently no dividends paid
Risk via 5d forecast
Volatility 65.2%
Value at Risk 5%th 97.5%
Relative Tail Risk -9.06%
Reward TTM
Sharpe Ratio -0.49
Alpha -49.43
CAGR/Max DD -0.49
Character TTM
Hurst Exponent 0.493
Beta 0.563
Beta Downside 0.900
Drawdowns 3y
Max DD 94.17%
Mean DD 61.22%
Median DD 72.85%

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.

Piotroski VR‑10 (Strict, 0-10) 0.0

Net Income (-280.5m TTM) > 0 and > 6% of Revenue (6% = 707.2k TTM)
FCFTA -0.53 (>2.0%) and ΔFCFTA -27.32pp (YES ≥ +1.0pp, WARN ≥ +0.5pp)
NWC/Revenue 2448 % (prev 366.4%; Δ 2082 pp) (YES ≤20% & Δ≤-1pp; WARN ≤25% & Δ≤0 oder ≤40% & Δ≤-3pp)
CFO/TA -0.53 (>3.0%) and CFO -188.0m > Net Income -280.5m (YES >=105%, WARN >=100%)
NO Net Debt/EBITDA fails (EBITDA <= 0)
Current Ratio 6.61 (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 0.07% (target <= -2.0% for YES)
Gross Margin -153.3% (prev 9.80%; Δ -163.1pp) >=18% & Δ>=+0.5pp (WARN >=15% & Δ>=0)
Asset Turnover 2.49% (prev 22.40%; Δ -19.92pp) >=50% & Δ>=+2pp (WARN >=35% & Δ>=0)
Interest Coverage Ratio -11.30 (EBITDA TTM -217.8m / Interest Expense TTM 19.4m) >= 6 (WARN >= 3)

Altman Z'' -34.11

(A) 0.82 = (Total Current Assets 340.0m - Total Current Liabilities 51.4m) / Total Assets 352.6m
(B) -3.76 = Retained Earnings (Balance) -1.32b / Total Assets 352.6m
warn (B) unusual magnitude: -3.76 — check mapping/units
(C) -0.46 = EBIT TTM -218.7m / Avg Total Assets 473.9m
(D) -22.98 = Book Value of Equity -1.32b / Total Liabilities 57.6m
Total Rating: -34.11 = (6.56 * A) + (3.26 * B) + (6.72 * C) + (1.05 * D)

ValueRay F-Score (Strict, 0-100) 28.28

1. Piotroski 0.0pt
2. FCF Yield -94.18%
3. FCF Margin data missing
4. Debt/Equity 0.03
5. Debt/Ebitda 1.48
6. ROIC - WACC (= -65.18)%
7. RoE -72.66%
8. Rev. Trend 4.90%
9. EPS Trend -11.62%

What is the price of PRTA shares?

As of December 27, 2025, the stock is trading at USD 9.54 with a total of 424,645 shares traded.
Over the past week, the price has changed by +3.58%, over one month by -8.53%, over three months by +1.38% and over the past year by -39.39%.

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 20.3 113.1%
Analysts Target Price 20.3 113.1%
ValueRay Target Price 7.3 -23.6%

PRTA Fundamental Data Overview December 26, 2025

Market Cap USD = 521.6m (521.6m USD * 1.0 USD.USD)
P/E Forward = 11.7096
P/S = 44.257
P/B = 1.7317
P/EG = 0.8
Beta = -0.104
Revenue TTM = 11.8m USD
EBIT TTM = -218.7m USD
EBITDA TTM = -217.8m USD
Long Term Debt = 9.08m USD (from capitalLeaseObligations, last quarter)
Short Term Debt = 2.88m USD (from shortTermDebt, last quarter)
Debt = 9.08m USD (from shortLongTermDebtTotal, last quarter)
Net Debt = -321.8m USD (from netDebt column, last quarter)
Enterprise Value = 199.9m USD (521.6m + Debt 9.08m - CCE 330.8m)
Interest Coverage Ratio = -11.30 (Ebit TTM -218.7m / Interest Expense TTM 19.4m)
FCF Yield = -94.18% (FCF TTM -188.2m / Enterprise Value 199.9m)
FCF Margin = -1597 % (FCF TTM -188.2m / Revenue TTM 11.8m)
Net Margin = -2380 % (Net Income TTM -280.5m / Revenue TTM 11.8m)
Gross Margin = -153.3% ((Revenue TTM 11.8m - Cost of Revenue TTM 29.9m) / Revenue TTM)
Gross Margin QoQ = -1098 % (prev 100.0%)
Tobins Q-Ratio = 0.57 (Enterprise Value 199.9m / Total Assets 352.6m)
Interest Expense / Debt = 72.11% (Interest Expense 6.55m / Debt 9.08m)
Taxrate = -1.03% (negative due to tax credits) (371.0k / -36.2m)
NOPAT = -220.9m (EBIT -218.7m * (1 - -1.03%)) [loss with tax shield] [negative tax rate / tax credits]
Current Ratio = 6.61 (Total Current Assets 340.0m / Total Current Liabilities 51.4m)
Debt / Equity = 0.03 (Debt 9.08m / totalStockholderEquity, last quarter 295.0m)
Debt / EBITDA = 1.48 (negative EBITDA) (Net Debt -321.8m / EBITDA -217.8m)
Debt / FCF = 1.71 (negative FCF - burning cash) (Net Debt -321.8m / FCF TTM -188.2m)
Total Stockholder Equity = 386.0m (last 4 quarters mean from totalStockholderEquity)
RoA = -79.53% (Net Income -280.5m / Total Assets 352.6m)
RoE = -72.66% (Net Income TTM -280.5m / Total Stockholder Equity 386.0m)
RoCE = -55.35% (EBIT -218.7m / Capital Employed (Equity 386.0m + L.T.Debt 9.08m))
RoIC = -57.23% (negative operating profit) (NOPAT -220.9m / Invested Capital 386.0m)
WACC = 7.95% (E(521.6m)/V(530.7m) * Re(8.09%) + (debt cost/tax rate unavailable))
Discount Rate = 8.09% (= CAPM, Blume Beta Adj.)
Shares Correlation 3-Years: 100.0 | Cagr: 0.15%
Fair Price DCF = unknown (Cash Flow -188.2m)
EPS Correlation: -11.62 | EPS CAGR: 0.94% | SUE: -0.16 | # QB: 0
Revenue Correlation: 4.90 | Revenue CAGR: 21.26% | SUE: -0.10 | # QB: 0
EPS next Quarter (2026-03-31): EPS=-0.32 | Chg30d=-0.060 | Revisions Net=+2 | Analysts=2
EPS next Year (2026-12-31): EPS=0.53 | Chg30d=+1.249 | Revisions Net=+1 | Growth EPS=+111.6% | Growth Revenue=+1051.7%

Additional Sources for PRTA Stock

News: Wall Street Journal | Benzinga | Yahoo Finance
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Fund Manager Positions: Dataroma | Stockcircle