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Protagonist TherapeuticsPTGX -2.96%53 Cyclically Adjusted PB Ratio is 19.52 as of Sep. 16, 2026, which is 85% above its 10-year median of 10.54. GuruFocus rates PTGX with a GF Score™ of 53/100 and a GF Value™ of $99.10 (Significantly Overvalued). The stock has 6 warning signs investors should review. Among 680 Biotechnology companies, Protagonist Therapeutics ranks worse than 93.82% on this metric.
The historical rank and industry rank for Protagonist Therapeutics's Cyclically Adjusted PB Ratio or its related term are showing as below:
PTGX'
s Cyclically Adjusted PB Ratio Range Over the Past 10 Years
Min: 6.58 Med: 10.54 Max: 21.1
Current: 20.16
During the past years, Protagonist Therapeutics's highest Cyclically Adjusted PB Ratio was 21.10. The lowest was 6.58. And the median was 10.54.
PTGX's Cyclically Adjusted PB Ratio is ranked worse than 93.82% of 680
companies
in the Biotechnology industry
Industry Median: 1.575
vs PTGX: 20.16
The Shiller PE Ratio was first used by professor Robert Shiller. He uses E10 for his Shiller PE Ratio calculation. E10 is the average of the inflation adjusted earnings per share of a company over the past 10 years. The similar calculation is applied by GuruFocus to calculate the Cyclically Adjusted PB Ratio. The Cyclically Adjusted Book per Share is the average of the inflation adjusted book value per share of a company over the past 10 years.
Protagonist Therapeutics's adjusted book value per share data for the three months ended in Jun. 2026 was $13.012. Add all the adjusted book value per share for the past 10 years together and divide the count will get our Cyclically Adjusted Book per Share, which is $7.35 for the trailing ten years ended in Jun. 2026.
Shiller PE for Stocks: The True Measure of Stock Valuation
Protagonist Therapeutics (NAS:PTGX) Cyclically Adjusted PB Ratio Explanation
Compared with the regular PB Ratio, which works poorly for cyclical businesses, the Cyclically Adjusted PB Ratio smoothed out the fluctuations of book value during business cycles. Therefore it is more accurate in reflecting the valuation of the company.
If a company has consistent business performance, the Cyclically Adjusted PB Ratio should give similar results to regular PB Ratio.
Protagonist Therapeutics Cyclically Adjusted PB Ratio Related Terms
Protagonist Therapeutics Cyclically Adjusted PB Ratio Historical Data
* Premium members only.
The historical data trend for Protagonist Therapeutics's Cyclically Adjusted PB Ratio 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.
Protagonist Therapeutics Cyclically Adjusted PB Ratio Chart
PTGX vs PRAX, CRNX, PCVX: Cyclically Adjusted PB Ratio Comparison
For the Biotechnology subindustry, Protagonist Therapeutics's Cyclically Adjusted PB Ratio, along with its competitors' market caps and Cyclically Adjusted PB 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.
Protagonist Therapeutics Cyclically Adjusted PB Ratio vs Biotechnology Industry
For the Biotechnology industry and Healthcare sector, Protagonist Therapeutics's Cyclically Adjusted PB Ratio distribution charts can be found below:
* The bar in red indicates where Protagonist Therapeutics's Cyclically Adjusted PB Ratio falls into.
Protagonist Therapeutics Cyclically Adjusted PB Ratio Calculation
Like the Shiller PE Ratio, the Cyclically Adjusted PB Ratio takes the Book Value per Share from the past 10 years, adjusts it for inflation, and then calculates the average. This average is then used for the P/B calculation. Because it considers this 10-year average, it's often referred to as the CAPB Ratio.
The Shiller PE Ratio was first used by professor Robert Shiller to measure the valuation of the overall market. The similar calculation is applied by GuruFocus to calculate the Cyclically Adjusted PB Ratio.
* 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.
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.
What does a Cyclically Adjusted PB Ratio of 19.52 mean?
Protagonist Therapeutics (PTGX) has a Cyclically Adjusted PB Ratio of 19.52 as of Sep. 16, 2026. Cyclically Adjusted PB Ratio is the ratio of share price to a company's inflation-adjusted book value per share over a 10-year period. View historical data on Protagonist Therapeutics and its competitors. This is 85% above median its historical median of 10.54. Over the past decade, Protagonist Therapeutics' Cyclically Adjusted PB Ratio has ranged from 6.58 to 21.10. According to the industry distribution chart, Protagonist Therapeutics ranks #638 out of 680 companies in the Biotechnology industry, placing it in the top 93.8%.
Is Protagonist Therapeutics' Cyclically Adjusted PB Ratio too high?
Protagonist Therapeutics' current Cyclically Adjusted PB Ratio of 19.52 is 85% above median its 10-year median of 10.54. Over the past 10 years, this metric has ranged from a low of 6.58 to a high of 21.10. The Biotechnology industry median Cyclically Adjusted PB Ratio is 1.58. Protagonist Therapeutics' value of 19.52 is 1139.4% above this industry median. Based on the distribution chart, Protagonist Therapeutics ranks #638 out of 680 companies in the Biotechnology industry, which is in the bottom quartile relative to peers. Overall, Protagonist Therapeutics has a GF Score™ of 53/100 and is considered Significantly Overvalued, reflecting its overall financial health beyond just this single metric.
How does Protagonist Therapeutics' Cyclically Adjusted PB Ratio compare to PRAX and CRNX?
According to the Biotechnology industry distribution chart, Protagonist Therapeutics ranks #638 out of 680 companies for Cyclically Adjusted PB Ratio. This places Protagonist Therapeutics in the lower half of its industry. The industry median Cyclically Adjusted PB Ratio is 1.58. Protagonist Therapeutics' value of 19.52 is 1139.4% above this benchmark. Historically, Protagonist Therapeutics' own Cyclically Adjusted PB Ratio has ranged from 6.58 to 21.10 over the past decade. While the company's 10-year median is 10.54 vs. the industry median of 1.58, Protagonist Therapeutics has consistently been above the industry average. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good Cyclically Adjusted PB Ratio for a Biotechnology company?
The median Cyclically Adjusted PB Ratio among Biotechnology companies is 1.58, based on 680 companies in the industry. Companies in the top quartile (top 25%) have a Cyclically Adjusted PB Ratio significantly above this median, while those in the bottom quartile fall well below. However, Cyclically Adjusted PB Ratio should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Protagonist Therapeutics's current Cyclically Adjusted PB Ratio of 19.52 is 1139.4% above the industry median. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high Cyclically Adjusted PB Ratio mean?
A high Cyclically Adjusted PB Ratio can signal that a stock is expensive relative to its fundamentals. Cyclically Adjusted PB Ratio is the ratio of share price to a company's inflation-adjusted book value per share over a 10-year period. View historical data on Protagonist Therapeutics and its competitors. For the Biotechnology industry, the median Cyclically Adjusted PB Ratio is 1.58 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Protagonist Therapeutics's current Cyclically Adjusted PB Ratio is 19.52, which is 85% above median its own 10-year median of 10.54. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Protagonist Therapeutics stock overvalued right now?
Based on GuruFocus' analysis, Protagonist Therapeutics (PTGX) is currently considered Significantly Overvalued. The stock's GF Value™ is $99.10, compared to a current price of $143.54 — trading 44.8% above its estimated fair value. The current Cyclically Adjusted PB Ratio is 19.52, which is 85% above median its 10-year median of 10.54 and 1139.4% above the Biotechnology industry median of 1.58. Protagonist Therapeutics' overall GF Score™ is 53/100 with 6 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Cyclically Adjusted PB Ratio calculated?
Cyclically Adjusted PB Ratio is calculated from a company's financial statements. For Protagonist Therapeutics (PTGX), the current Cyclically Adjusted PB Ratio is 19.52 as of Sep. 16, 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 Protagonist Therapeutics (PTGX) Overvalued in 2026?
Based on GuruFocus' analysis, Protagonist Therapeutics stock appears to be overvalued.
The current stock price of $143.54 is trading 44.8% above its estimated GF Value™ of $99.10.
GuruFocus considers Protagonist Therapeutics to be Significantly Overvalued.
Key valuation signals for PTGX:
Cyclically Adjusted PB Ratio: 19.52 (85% above median its 10-year median of 10.54)
GF Value™: $99.10 vs. price of $143.54 (44.8% above fair value)
Industry Position: 1139.4% above the Biotechnology median (#638 of 680)
No single metric tells the full story. See the PTGX stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.
Protagonist Therapeutics Inc is a biopharmaceutical company engaged in the discovery and development of peptide-based therapeutics using its proprietary technology platform. The company focuses on three therapeutic areas: inflammation and immunology, hematology, and metabolic diseases. Its pipeline includes clinical-stage and preclinical candidates such as rusfertide for polycythemia vera, icotrokinra for inflammatory diseases, and other programs targeting IL-17, obesity, and iron metabolism disorders, developed through internal research and strategic collaborations.
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