PRTA Stock Analysis: Prothena | NASDAQ
Biotechnology | NASDAQ, USA | Market Cap: 440m USD | 12M Return: 2.7% | IE00B91XRN20 | Charts, Fundamentals & Technical Analysis
Avg Turnover: 3.36M
Qual. Beats: 0
Rev. Trend: -58.9%
Qual. Beats: 0
Warnings
Tailwinds
No distinct edge detected
Seasonality 11.6 years of data
How good or bad each month usually is (without trend). The score below shows how much you can trust it: 0 = pure chance, >40 gets interesting and >55 is strong.
Prothena Corporation plc is an Ireland-based, late-stage clinical biotechnology company that develops therapies for diseases driven by protein dysregulation, a class of conditions that includes neurodegenerative and amyloid disorders. The companys pipeline spans Phase 3 through preclinical assets, led by Prasinezumab (a monoclonal antibody for Parkinsons disease and other synucleinopathies, partnered with Roche) and Coramitug (an antibody for transthyretin amyloidosis cardiomyopathy). Earlier-stage programs target tau and amyloid-beta in Alzheimers disease, TDP-43 in ALS, and other neurodegenerative indications, with several assets developed under a master collaboration with Bristol Myers Squibb.
Prothenas business model reflects a common approach among small-cap clinical-stage biotechs: it advances internally discovered antibody candidates through early and mid-stage development, then relies on licensing and co-development deals with larger pharmaceutical companies (Roche, Bristol Myers Squibb) to fund later-stage trials, manufacturing, and global commercialization. Incorporated in 2012 and listed on NASDAQ, the company carries meaningful clinical and regulatory risk typical of the biotechnology sub-industry, as its valuation is tied to trial outcomes rather than current product revenue.
- Prasinezumab Phase 3 Parkinson data readout approaches
- Coramitug Phase 3 ATTR amyloidosis trial results pending
- Bristol Myers Squibb tau and TDP-43 collaboration drives milestone payments
| Net Income: -44.0m TTM > 0 and > 6% of Revenue |
| FCF/TA: -0.20 > 0.02 and ΔFCF/TA 28.26 > 1.0 |
| NWC/Revenue: 514.1% < 20% (prev 3.07k%; Δ -2.56k% < -1%) |
| CFO/TA -0.20 > 3% & CFO -60.0m > Net Income -44.0m |
| Net Debt/EBITDA: error (EBITDA <= 0) |
| Current Ratio: 25.05 > 1.5 & < 3 |
| Outstanding Shares: last quarter (52.1m) vs 12m ago -3.12% < -2% |
| Gross Margin: 93.21% > 18% (prev 65.33%; Δ 27.88% > 0.5%) |
| Asset Turnover: 15.54% > 50% (prev 2.59%; Δ 12.95% > 0%) |
| Interest Coverage Ratio: error (cannot be calculated; needs correct EBIT TTM and Interest Expense TTM) |
| A: 0.93 (Total Current Assets 292.0m - Total Current Liabilities 11.7m) / Total Assets 302.6m |
| B: -4.40 (Retained Earnings -1.33b / Total Assets 302.6m) |
| C: -0.12 (EBIT TTM -43.6m / Avg Total Assets 350.8m) |
| D: 18.29 (Book Value of Equity 286.9m / Total Liabilities 15.7m) |
| Altman-Z'' = 10.09 = AAA |
As of September 22, 2026, the stock is trading at USD 8.51 with a total of 363,158 shares traded. Over the past week, the price has changed by -3.95%, over one month by -9.95%, over three months by -6.99% and over the past year by +2.65%.
Current recommended Stop Loss: 8.00 (which is 6% or 1.3 ATR below the current price).
Prothena has received a consensus analysts rating of 3.50. Therefore, it is recommended to hold PRTA.
- StrongBuy: 1
- Buy: 2
- Hold: 2
- Sell: 1
- StrongSell: 0
| Analysts Target Price | 21.4 | 151.5% |
P/E Forward = 10.627
P/S = 8.0776
P/B = 1.5353
P/EG = 0.8
Revenue TTM = 54.5m USD
EBIT TTM = -43.6m USD
EBITDA TTM = -41.1m USD
Long Term Debt = 4.03m USD (estimated: total debt 6.99m - short term 2.96m)
Short Term Debt = 2.96m USD (from shortTermDebt, last quarter)
Debt = 6.99m USD (from shortLongTermDebtTotal, last quarter) (leases 6.99m already included)
Net Debt = -281.2m USD (calculated: Debt 6.99m - CCE 288.2m)
Enterprise Value = 159.3m USD (440.5m + Debt 6.99m - CCE 288.2m)
Interest Coverage Ratio = unknown (Ebit TTM -43.6m / Interest Expense TTM 0.0)
EV/FCF = -2.62x (Enterprise Value 159.3m / FCF TTM -60.7m)
FCF Yield = -38.12% (FCF TTM -60.7m / Enterprise Value 159.3m)
FCF Margin = -111.3% (FCF TTM -60.7m / Revenue TTM 54.5m)
Net Margin = -80.67% (Net Income TTM -44.0m / Revenue TTM 54.5m)
Gross Margin = 93.21% ((Revenue TTM 54.5m - Cost of Revenue TTM 3.70m) / Revenue TTM)
Gross Margin QoQ = none% (prev none%)
Tobins Q-Ratio = 0.53 (Enterprise Value 159.3m / Total Assets 302.6m)
Interest Expense / Debt = 0.0% (Interest Expense 0.0 / Debt 6.99m)
Taxrate = 21.0% (US federal default 21%)
NOPAT = -34.5m (EBIT -43.6m * (1 - 21.00%)) [loss with tax shield]
Current Ratio = 25.05 (Total Current Assets 292.0m / Total Current Liabilities 11.7m)
Debt / Equity = 0.02 (Debt 6.99m / totalStockholderEquity, last quarter 286.9m)
Debt / EBITDA = 6.84 (negative EBITDA) (Net Debt -281.2m / EBITDA -41.1m)
Debt / FCF = 4.63 (negative FCF - burning cash) (Net Debt -281.2m / FCF TTM -60.7m)
Total Stockholder Equity = 293.7m (last 4 quarters mean from totalStockholderEquity)
RoA = -12.54% (Net Income -44.0m / Total Assets 302.6m)
RoE = -14.98% (Net Income TTM -44.0m / Total Stockholder Equity 293.7m)
RoCE = -14.64% (EBIT -43.6m / Capital Employed (Equity 293.7m + L.T.Debt 4.03m))
RoIC = -11.83% (negative operating profit) (NOPAT -34.5m / Invested Capital 291.2m)
WACC = 10.55% (E(440.5m)/V(447.5m) * Re(10.72%) + D(6.99m)/V(447.5m) * Rd(0.0%) * (1-Tc(0.21)))
Discount Rate = 10.72% (= CAPM, Blume Beta Adj.)
Shares (quarterly) Correlation: -53.62 | Cagr: -1.31%
[DCF] Fair Price = unknown (Cash Flow -60.7m)
EPS Correlation: N/A | EPS CAGR: N/A | SUE: 0.08 | # QB: 0
Revenue Correlation: -58.91 | Revenue CAGR: -51.89% | SUE: 0.01 | # QB: 0
EPS current Quarter (2026-09-30): EPS=-0.38 | Chg30d=-1.33% | Revisions=+25% | Analysts=1
EPS current Year (2026-12-31): EPS=0.65 | Chg30d=+1.56% | Revisions=+40% | GrowthEPS=+116.3% | GrowthRev=+758.7%
EPS next Year (2027-12-31): EPS=-1.52 | Chg30d=-16.03% | Revisions=+25% | GrowthEPS=-333.8% | GrowthRev=-70.7%