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Prothena Corporation plc(PRTA)

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ADVISORIES YOU CAN VERIFY
QUALITY SIGNAL RECENCY
1-STAR RATING
SELL
SELL for 3 days
PROFIT SINCE LAST BUY
-11.87%
LAST CLOSE
$8.58
09/18/2026
(24-hour delay)

Advisory History & Simulated Performance *

*as per simulation (see disclosures)
  • ALL
  • 1Y
  • 1M
  • 1W
  • BUY Advisory
  • SELL Advisory (Profit)
  • SELL Advisory (Loss)
  • Profit
  • Loss
  • PASS (Skip)
Upturn Stock price based on last close iconStock price based on last close

Advisory Performance History (Simulated)Advisory Performance History info

Upturn Advisory & Investor View for PRTA

09/18/2026: PRTA (1-star) is a SELL. SELL for 3 days. Simulated Profits (-11.87%). Updated daily EoD!

How to Read the Upturn Advisory

The Upturn Star Rating and the current BUY, SELL, or PASS advisory are generated by Upturn’s AI advisory engine based on proprietary signal analysis, price behavior, advisory history, and historical signal performance.

Company fundamentals, valuation, risks, and news provide supporting context about the business.

Price Behavior

Downtrend
PRICE PATH

Downtrend

The stock has experienced a sustained decline in price over recent periods.

Moderately Choppy
PRICE STABILITY

Moderately Choppy

The stock has experienced noticeable price swings while retaining some directional structure.

Analysis of Past Performance

Type Stock
Historic Profit -26.51%
Avg. Invested days 26
Today’s Advisory SELL
Upturn Advisory Rating upturn star rating icon
Upturn Advisory Performance Upturn Advisory Performance icon 1.0
Stock Returns Performance Upturn Returns Performance icon 1.0
Upturn Profits based on simulation icon Profits based on simulation
Upturn last close icon Last Close 09/18/2026

Upturn Scorecard

Upturn Star Rating

PRTA receives a 3-star rating, supported by available scored pillars. The rating is constrained by soft unit economics, and weak price momentum.

Company Fundamentals

PRTA has moderate overall fundamentals (3 stars), with soft financial health, soft growth momentum, and strong ownership. In FY2025 versus FY2024, growth and ownership metrics are mixed: negative earnings growth (-99.6%), soft cash generation (FCF margin -1690.6%), negative revenue growth (-92.8%).

Financial Health Rating

PRTA's financial health is supported by moderate liquidity, including working-capital and asset support (WC/assets 83.9%). Cash strength is soft (2 stars), which helps explain the 2-star overall score.

Growth Momentum Score

PRTA's growth profile is soft, with the least-weak measure being free-cash-flow growth at -8.9% FY2025 versus FY2024. By comparison, while revenue growth (-92.8%, negative) and earnings growth (-99.6%, negative) hold the profile back, so recent growth is not broad-based across the business.

Ownership

Institutional ownership is 93.3% and approximately 68.0% of outstanding shares are publicly tradable, supporting liquidity and institutional participation. Insider ownership of 22.15% supports management-shareholder alignment.

Top 5 Institutional Investors

FMR Inc 14.71%
Rubric Capital Management LP 9.74%
BlackRock Inc 9.05%
State Street Corp 3.78%
D. E. Shaw & Co LP 3.14%

Unit Economics (Per $1K Revenue)

PRTA generates approximately $618 of gross profit, $-19,058 of operating income, and $-16,906 of free cash flow for every $1,000 of revenue. Based on FY2025 results. Strong cash conversion and healthy margins support the rating, although capital efficiency remains below the highest tier.

Economic Dimensions

Effective Tax Rate: -21.54% (Tax Credit)

Quantitative Style Profile

PRTA has a liquid, relatively low-volatility profile. Weak momentum is the primary drawback, while valuation that is moderately attractive rather than deeply discounted.

Style Classification

Quality Focused

Low VolatilitySmall / Mid Cap RiskShort Squeeze RiskHighly Liquid / Institution-Friendly

Key Highlights

Company Size Small-Cap Stock
Market Capitalization 440.47M USD
Price to earnings Ratio -
1Y Target Price 21.4
Price to earnings Ratio -
1Y Target Price 21.4
Volume (30-day avg) 409.5K shares
Beta -0.33
52 Weeks Range 7.73 - 11.80
Updated Date 09/19/2026
52 Weeks Range 7.73 - 11.80
Updated Date 09/19/2026
Dividends yield (FY) -
Basic EPS (TTM) -0.82

Analyzing Revenue: Products, Geography and Growth

Revenue by Products

Product revenue - Year on Year

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Valuation

Trailing PE -
Forward PE 10.63
Enterprise Value 159.27M
Price to Sales(TTM) 8.08
Enterprise Value 159.27M
Price to Sales(TTM) 8.08
Enterprise Value to Revenue 2.92
Enterprise Value to EBITDA -3.58
Shares Outstanding 51.34M
Shares Floating 34.91M
Shares Outstanding 51.34M
Shares Floating 34.91M
Percent Insiders 22.15
Percent Institutions 93.28

Financial Metrics

🧭 Investment Snapshot

Total Revenue (Scale)

Information icon Total money earned from selling products or services before any costs. It is needed to understand the scale of the business and its ability to generate income.

Net Income (Profit)

Information icon Final profit after all expenses, interest, and taxes are deducted. It is needed to determine the overall profitability available to shareholders.

Free Cash Flow (Cash Strength)

Information icon Cash remaining after operating activities and capital expenditures, showing cash available for growth. It is needed to evaluate the company’s ability to invest, pay dividends, or reduce debt.

📈 Growth & Strength

Operating Income (Core Profit)

Information icon Profit from core operations after deducting all operating expenses. It is needed to measure how efficiently the company runs its primary business activities.

EBITDA (Cash Earnings)

Information icon Earnings before interest, taxes, depreciation, and amortization, indicating operating cash potential. It is needed to compare operating performance across companies without accounting or financing differences.

Gross Profit (Unit Profitability)

Information icon Revenue minus cost of revenue, showing profit after direct production costs. It is needed to evaluate core business profitability before overhead expenses.

🛡️ Financial Safety

Cash (Liquidity Buffer)

Information icon Total cash and cash equivalents on hand. It is needed to evaluate immediate liquidity and financial flexibility.

Total Debt (Leverage Risk)

Information icon Total debt including both short-term and long-term components. It is needed to assess the company’s leverage and financial risk.

Net Working Capital (Short-Term Health)

Information icon Current assets minus current liabilities, indicating short-term liquidity strength. It is needed to assess whether the company can meet its short-term obligations.

🧱 Balance Sheet Strength

Stockholder Equity (Net Worth)

Information icon Total equity value held by shareholders. It is needed to understand the net worth of the company from the owners’ perspective.

Total Assets (Asset Base)

Information icon The full value of everything the company owns, including cash, inventory, equipment, and investments. It is needed to understand the resource base used to generate revenue.

Income Before Tax (Pre-Tax Earnings)

Information icon Income before provision for income taxes. It is needed to analyze profitability independent of tax structures.

⚙️ Cost & Drag Factors

Cost of Revenue (Production Cost)

Information icon Direct costs required to produce and deliver the products or services sold. It is needed to assess efficiency in production and service delivery.

Total Operating Expenses (Operating Cost)

Information icon Indirect costs of running the business such as salaries, marketing, and administration. It is needed to understand how much it costs to sustain ongoing business operations.

Income Tax Expense (Tax Drag)

Information icon Amount of taxes paid or payable to the government. It is needed to evaluate the impact of taxation on overall profitability.

About Prothena Corporation plc

Exchange NASDAQ
Headquarters -
IPO Launch date 2012-12-21
President, CEO & Director Dr. Gene G. Kinney Ph.D.
Sector Healthcare
Industry Biotechnology
Full time employees 67
Full time employees 67

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.