Prothena Corporation plc (PRTA) Fair Value 2026

PRTA · Biotechnology ·

By CirclFi Research Team · Data from SEC EDGAR, FRED & GDELT

Quality Score

7.0 /10

32 fundamental signals · 1 models active

Value Trap Risk

LOW (26/100)

Quick Summary — As of 2026-08-28, Prothena Corporation plc (PRTA) trades at $9.33. QOC: 7.0/10. Value Trap Risk: 26/100 (LOW). 1/13 models active.

Key Facts

Ticker
PRTA
Price
$9.33
Quality Score
7.0/10
Value Trap Risk
26/100
Models Active
1/13
Last Updated
Strength: 1 independent models provide multi-angle coverage
Risk: Majority of models suggest overvaluation

What Fair Value Does Each Model Give PRTA?

1 Intrinsic Value Models vs. Current Price ($9.33)

Core Models (Unlocked)
Model Fair Value Upside
Relative · Low Conviction
 $5.78 -38.0%

All Models Active

All 1 models are displayed above.

What Is Prothena Corporation plc (PRTA) Worth in 2026?

According to the CirclFi Deep Alpha Valuation Engine, Prothena Corporation plc's intrinsic value is estimated at $5.78, suggesting the stock is overvalued at its current price of $9.33. With 1 out of 1 models flagging downside (-38.0% vs price), the market may be pricing in unsustainable growth.

What Do the Models Say About PRTA?

1 of 13 models are currently active for PRTA. All 1 active models suggest the stock trades above fair value. See which stocks rank higher →

How Does PRTA Rank in Biotechnology?

Among 625 Biotechnology stocks, PRTA ranks #49 by Quality of Company score. CirclFi's QOC score of 7.0/10 evaluates 32 fundamental signals. A score of 7.0 indicates above-average quality.

See all Most Undervalued Biotechnology Stocks →

As a biotechnology enterprise, Prothena Corporation plc operates in a sector where pipeline depth and stage distribution is a critical driver of valuation. Investors evaluating PRTA should weigh these sector-specific dynamics alongside our model-derived fair values.

Is PRTA a Value Trap?

CirclFi's Value Trap algorithm assigns PRTA a score of 26/100 (LOW). This indicates low risk. The financial profile does not exhibit typical value trap warning signs. The score cross-references apparent undervaluation against fundamental deterioration signals. Browse lowest value-trap stocks →

Multi-Model Methodology

1 of 13 models are active for Prothena Corporation plc. Limited activation may indicate insufficient history. Each model applies a fundamentally different valuation philosophy. See the complete methodology →

According to the CirclFi 32-factor quality framework, Prothena Corporation plc's fundamental quality profile registers 7.0/10. This respectable score captures the company's profitability depth, growth consistency, balance sheet resilience, and shareholder return track record.

CirclFi runs 13 independent models for each stock. Browse all stocks with 13-model coverage →

Data Sources & Confidence

Every PRTA valuation is built from SEC EDGAR XBRL filings — 700+ standardized financial tags. Macroeconomic context from FRED calibrates discount rates, while GDELT news sentiment feeds into our Sentiment SOTP model. All pipelines run daily. Read the complete data methodology →

Across PRTA's 1 active models, average confidence is 17%. Lower confidence may reflect limited history or high volatility.

CirclFi's output is a research starting point, not a buy/sell signal. All data updates daily. Read the full methodology →

This analysis is produced by the CirclFi Valuation Engine using quantitative models applied to SEC EDGAR filings, public market feeds, and FRED macroeconomic indicators. It is not financial advice.

Read the full investment analysis: Should You Buy Prothena Corporation plc Stock in 2026? →

Bull case, bear case, risk factors & peer comparison — updated daily

Which Similar Biotechnology Stocks Should You Also Analyze?

11 related Biotechnology stocks with 13-model coverage

ANABAnaptysBio, Inc.QOC 7.0ADAGAdagene Inc.QOC 7.0MGTXMeiraGTx Holdings plcQOC 7.0GMABGenmab A/SQOC 6.9SEERSeer, Inc.QOC 7.0IDYAIDEAYA Biosciences, Inc.QOC 6.9IVVDInvivyd, Inc.QOC 5.6KTTAPasithea Therapeutics Corp.QOC 4.8ARMPArmata Pharmaceuticals, Inc.QOC 4.1EXELExelixis, Inc.QOC 9.6INCYIncyte CorporationQOC 9.5

Read investment analysis: ANAB · ADAG · MGTX · GMAB · SEER · IDYA · IVVD · KTTA · ARMP · EXEL · INCY

Which Other Stocks Have a Similar Quality Score to PRTA?

5 companies across all industries closest to PRTA’s Quality of Company score of 7.0/10.

YRDYiren Digital Ltd.QOC 7.0DCODucommun IncorporatedQOC 7.0HROWHarrow, Inc.QOC 7.0MEIMethode Electronics, Inc.QOC 7.0NVDANVIDIA CorporationQOC 10.0

Read investment analysis: YRD · DCO · HROW · MEI · NVDA

Where Does PRTA Sit in CirclFi's Biotechnology Rankings?

PRTA is ranked against every other Biotechnology stock CirclFi covers in each of these screens.

See all Biotechnology stocks ranked →

What Else Do Investors Ask About Prothena Corporation plc’s Valuation?

What is Prothena Corporation plc's intrinsic value in 2026?

CirclFi does not yet have enough active models to publish a median fair value for Prothena Corporation plc (PRTA). The Quality of Company score is 7.0/10 across 32 fundamental signals. All models use SEC EDGAR filings updated daily. See our methodology page for how each model works.

Is PRTA overvalued or undervalued right now?

At $9.33, 0 of 1 active models suggest PRTA may be undervalued, while 1 indicate potential overvaluation. The assessment depends on which methodology best fits Prothena Corporation plc's business model in Biotechnology.

What does a Quality of Company score of 7.0 mean for PRTA?

Prothena Corporation plc's QOC of 7.0/10 reflects 32 fundamental signals: profitability margins, revenue growth consistency, balance sheet leverage, free cash flow generation, and capital allocation efficiency. Scores above 7 indicate strong fundamentals and disciplined management.

How many valuation models does CirclFi run on PRTA?

CirclFi analyzes PRTA with 13 institutional-grade models daily: Bayesian DCF (Monte Carlo + jump-diffusion), EPV (Greenwald zero-growth), EROIC Spread (McKinsey reinvestment), First Chicago (3-scenario), Markov DDM (regime-switching), ML-RIV (machine learning residual income), Dynamic NAV (asset-based), PWERM (option-theoretic), Regime Cross-Sectional (relative), Sentiment SOTP (hybrid), CUCE Ensemble (meta-model), FTNN Topology (neural network), and RCMH-DCF (conditional regime). Currently 1 of 13 are active for this stock. Read the full methodology →

Is PRTA a value trap in 2026?

Prothena Corporation plc's Value Trap score is 26/100 (LOW). This low score indicates the current valuation is not artificially depressed by fundamental deterioration, suggesting genuine opportunity rather than a trap. Browse stocks by value-trap risk →

Cite this analysis — “CirclFi assigns Prothena Corporation plc (PRTA) a Quality of Company score of 7.0/10 across 32 fundamental signals as of 2026-08-28.” Source: circlfi.com/stock/PRTA/ · Methodology
Primary sources for this PRTA valuation
  • Financial statements: Prothena Corporation plc 10-K and 10-Q filings on SEC EDGAR (CIK 0001559053) — 700+ standardized XBRL tags, published by the U.S. Securities and Exchange Commission.
  • Discount-rate inputs: FRED, Federal Reserve Bank of St. Louis — risk-free rates, VIX, yield curve, inflation.
  • News sentiment: The GDELT Project — global media tone, input to the Sentiment SOTP model.
  • Model definitions: CirclFi methodology — the published specification for all 13 models, including the academic sources each one implements.

Market data for PRTA as of ; valuations recomputed .