Prothena (STU:0PT) E10: €-2.72 (As of Mar. 2026)


STU:0PT Prothena Corp PLC STU:0PT
74 GF Score
Price €8.68
GF Value €12.86
! 3 Warning Signs
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What is Prothena E10?

Prothena STU:0PT -0.39% 74 E10 is €-2.72 as of Mar. 2026. GuruFocus rates STU:0PT with a GF Score™ of 74/100 and a GF Value™ of €12.86. The stock has 3 warning signs investors should review.

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller P/E calculation. E10 is the average of the inflation adjusted earnings of a company over the past 10 years.

Prothena's adjusted earnings per share data for the three months ended in Mar. 2026 was €0.519. Add all the adjusted EPS for the past 10 years together and divide 10 will get our e10, which is €-2.72 for the trailing ten years ended in Mar. 2026.

During the past 3 years, the average E10 Growth Rate was -7.00% per year. Please click Growth Rate Calculation Example (GuruFocus) to see how GuruFocus calculates Wal-Mart Stores Inc (WMT)'s revenue growth rate. You can apply the same method to get the E10 growth rate using E10 data.

During the past 13 years, the highest 3-Year average E10 Growth Rate of Prothena was -7.00% per year. The lowest was -7.10% per year. And the median was -7.05% per year.

As of today (2026-06-30), Prothena's current stock price is €8.684. Prothena's E10 for the quarter that ended in Mar. 2026 was €-2.72. Prothena's Shiller PE Ratio of today is .


Prothena  (STU:0PT) E10 Explanation

If a company grows much fast than inflation, E10 may underestimate the company's earnings power. Shiller PE Ratio can seem to be too high even the actual P/E is low.

For the Shiller P/E, the earnings of the past 10 years are inflation-adjusted and averaged. The result is used for P/E calculation. Since it looks at the average over the last 10 years, the Shiller P/E is also called PE10.

The Shiller P/E was first used by professor Robert Shiller to measure the valuation of the overall market. The same calculation is applied here to individual companies.


Be Aware

Shiller PE Ratio works better for cyclical companies. It gives you a better idea on the company's real earnings power.


Prothena E10 Related Terms


Prothena E10 Historical Data

* Premium members only.

The historical data trend for Prothena's E10 can be seen below:

* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD.
* For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.

Prothena E10 Chart

Prothena Annual Data
Trend Dec16 Dec17 Dec18 Dec19 Dec20 Dec21 Dec22 Dec23 Dec24 Dec25
E10
Get a 7-Day Free Trial Premium Member Only Premium Member Only -2.10 -2.48 -2.73 -3.22 -2.83

Prothena Quarterly Data
Jun21 Sep21 Dec21 Mar22 Jun22 Sep22 Dec22 Mar23 Jun23 Sep23 Dec23 Mar24 Jun24 Sep24 Dec24 Mar25 Jun25 Sep25 Dec25 Mar26
E10 Get a 7-Day Free Trial Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only -2.97 -2.88 -2.83 -2.83 -2.72

STU:0PT vs CTNM, ASMB, ARVN: E10 Comparison

For the Biotechnology subindustry, Prothena's Shiller PE Ratio, along with its competitors' market caps and Shiller PE Ratio data, can be viewed below:

* Competitive companies are chosen from companies within the same industry, with headquarter located in same country, with closest market capitalization; x-axis shows the market cap, and y-axis shows the term value; the bigger the dot, the larger the market cap. Note that "N/A" values will not show up in the chart.


Prothena Shiller PE Ratio vs Biotechnology Industry

For the Biotechnology industry and Healthcare sector, Prothena's Shiller PE Ratio distribution charts can be found below:

* The bar in red indicates where Prothena's Shiller PE Ratio falls into.


STU:0PT
74GF Score
Prothena Corp PLC STU:0PT
E10 is just one metric. See GF Score™, valuation, warning signs, and more.
View Full Analysis

Prothena E10 Calculation

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller P/E calculation. When we calculate the today's Shiller P/E ratio of a stock, we use today's price divided by E10.

What is E10? How do we calculate E10?

E10 is the average of the inflation adjusted earnings of a company over the past 10 years. Let's use an example to explain.

If we want to calculate the E10 of Wal-Mart (WMT) for Dec. 31, 2010, we need to have the inflation data and the earnings from 2001 through 2010.

We adjusted the earnings of 2001 earnings data with the total inflation from 2001 through 2010 to the equivalent earnings in 2010. If the total inflation from 2001 to 2010 is 40%, and Wal-Mart earned $1 a share in 2001, then the 2001's equivalent earnings in 2010 is $1.4 a share. If Wal-Mart earns $1 again in 2002, and the total inflation from 2002 through 2010 is 35%, then the equivalent 2002 earnings in 2010 is $1.35. So on and so forth, you get the equivalent earnings of past 10 years. Then you add them together and divided the sum by 10 to get E10.

Please note that we use the CPI data of the country/region where the company is headquartered. If the CPI data for that country/region is not available, then we will use the CPI data of the United States as default.

For example, Prothena's adjusted earnings per share data for the three months ended in Mar. 2026 was:

Adj_EPS= Earnings per Share (Diluted) /CPI of Mar. 2026 (Change)*Current CPI (Mar. 2026)
=0.519/125.8201*125.8201
=0.519

Current CPI (Mar. 2026) = 125.8201.

Prothena Quarterly Data

per share eps CPI Adj_EPS
201606 -1.050 101.072 -1.307
201609 -1.123 100.274 -1.409
201612 -1.337 99.676 -1.688
201703 -0.926 100.374 -1.161
201706 -0.409 100.673 -0.511
201709 -1.149 100.474 -1.439
201712 -1.048 100.075 -1.318
201803 -1.022 100.573 -1.279
201806 -1.284 101.072 -1.598
201809 -0.531 101.371 -0.659
201812 -0.492 100.773 -0.614
201903 -0.460 101.670 -0.569
201906 -0.354 102.168 -0.436
201909 -0.445 102.268 -0.547
201912 -0.486 102.068 -0.599
202003 -0.534 102.367 -0.656
202006 -0.586 101.769 -0.724
202009 -0.654 101.072 -0.814
202012 -0.633 101.072 -0.788
202103 -0.764 102.367 -0.939
202106 0.481 103.364 0.585
202109 1.811 104.859 2.173
202112 -0.628 106.653 -0.741
202203 -0.708 109.245 -0.815
202206 -0.832 112.779 -0.928
202209 -0.980 113.504 -1.086
202212 0.113 115.436 0.123
202303 -0.831 117.609 -0.889
202306 -0.951 119.662 -1.000
202309 0.356 120.749 0.371
202312 -1.155 120.749 -1.204
202403 -1.233 120.990 -1.282
202406 1.133 122.318 1.165
202409 -0.991 121.594 -1.025
202412 -1.031 122.439 -1.059
202503 -1.036 123.405 -1.056
202506 -2.029 124.492 -2.051
202509 -0.579 124.854 -0.583
202512 -0.342 125.820 -0.342
202603 0.519 125.820 0.519

Add all the adjusted EPS together and divide 10 will get our e10.

Frequently Asked Questions Learn more about E10 →
What does a E10 of €-2.72 mean?
Prothena (STU:0PT) has a E10 of €-2.72 as of Mar. 2026. E10 represents the company's inflation-adjusted earnings per share over a 10-year period. View historical data on Prothena and its competitors.
Is Prothena's E10 too high?
Prothena's current E10 is €-2.72. Overall, Prothena has a GF Score™ of 74/100, reflecting its overall financial health beyond just this single metric.
How does Prothena's E10 compare to CTNM and ASMB?
Prothena's E10 of €-2.72 can be compared against companies in the Biotechnology industry. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good E10 for a Biotechnology company?
A good E10 depends on the Biotechnology industry context. However, E10 should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high E10 mean?
A high E10 can signal that a stock is expensive relative to its fundamentals. E10 represents the company's inflation-adjusted earnings per share over a 10-year period. View historical data on Prothena and its competitors. Prothena's current E10 is €-2.72. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Prothena stock overvalued right now?
Prothena (STU:0PT) has a current E10 of €-2.72. The stock's GF Value™ is €12.86, compared to a current price of €8.68 — trading 32.5% below its estimated fair value. The current E10 is €-2.72. Prothena's overall GF Score™ is 74/100 with 3 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is E10 calculated?
E10 is calculated from a company's financial statements. For Prothena (STU:0PT), the current E10 is €-2.72 as of Mar. 2026. GuruFocus calculates this using data sourced from SEC filings and annual reports. See the calculation section and 30-year financial data on this page for the full breakdown.

Is Prothena (STU:0PT) Overvalued in 2026?

Based on GuruFocus' analysis, Prothena stock appears to be undervalued. The current stock price of €8.68 is trading 32.5% below its estimated GF Value™ of €12.86.

Key valuation signals for STU:0PT:

  • E10: €-2.72
  • GF Value™: €12.86 vs. price of €8.68 (32.5% below fair value)
  • GF Score™: 74/100 with 3 warning signs

No single metric tells the full story. See the STU:0PT stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.


Prothena Business Description

Other Exchanges PRTA:USA0Y3M:UK0PT:Germany
Address 77 Sir John Rogerson’s Quay, Block C, Grand Canal Docklands, Dublin 2, Dublin, IRL, D02 VK60
Prothena Corp PLC is a late-stage clinical biotechnology company that focuses on protein dysregulation and a pipeline of investigational therapeutics with the potential to change the course of devastating neurodegenerative and rare and peripheral amyloid diseases. Prothena is developing and applying its proprietary CYTOPE technology to target a broad spectrum of intracellular disease pathways in the brain and periphery. The company's pipeline includes both wholly-owned and partnered programs like Prasinezumab, Coramitug (PRX004), BMS-986446 (PRX005), PRX019, TDP-43 CYTOPE, and PRX012-TfR, being developed for the potential treatment of Parkinson's disease, ATTR amyloidosis with cardiomyopathy, Alzheimer's disease, Amyotrophic lateral sclerosis (ALS), and other neurodegenerative diseases.
74GF Score

Get the complete analysis for STU:0PT

E10 is just one metric. See GF Value™, 30-year financials, guru trades, warning signs, and more.

€8.68
Price
€12.86
GF Value