On this page we presented the PTGX PE Ratio History information for Protagonist Therapeutics' stock. The average PTGX PE ratio history based on using the annualized quarterly earnings result at each measurement period (for the "E" in the PE calculation; and the closing price on earnings date as the "P") is 129.9. Meanwhile, using the trailing twelve month (TTM) quarterly earnings result as our method of calculation the "E" value at each measurement period, the average PTGX PE ratio history based on this TTM earnings result method is 44.7. Note: any PE calculations involving negative earnings were discarded as not meaningful.

Let's now compare this PTGX PE ratio history result, against the recent PE: when this page was posted on 6/25/2026, the most recent closing price for PTGX had been 122.63, and the most recent quarterly earnings result, annualized, was 0.2. Meanwhile, the most recent TTM earnings summed to 0.62. From these numbers, we calculate the recent PTGX PE on 6/25/2026 based on annualized quarterly EPS was 613.1. Based on PTGX's history, that recent PE is elevated relative to the historical average, with the recent PE 372.0% higher than the historical average PE across our data set for Protagonist Therapeutics. Looking at the recent PTGX PE on 6/25/2026 based on TTM EPS, we calculate the ratio at 197.8. Based on PTGX's history, that recent PE is elevated relative to the historical average, with the recent PE 342.5% higher than the historical average PE across our Protagonist Therapeutics data set with TTM EPS used in the calculation at each period.

For self directed investors doing their due diligence on PTGX or any other given stock, valuation analysis for PTGX can greatly benefit from studying the past earnings and resulting PE ratio history calculations. This type of study can help inform an analysis as to whether the earnings trajectory over time and current versus historical average PE ratios justify the current stock market value.

That's why we bring you HistoricalPERatio.com to make it easy for investors to investigate Protagonist Therapeutics PE ratio history — or the PE history for any stock in our coverage universe. And in your continued research we hope you will be sure to check out the further links included for next earnings dates and also historical earnings surprises history for PTGX. Thanks for visiting, and the next time you need to research PTGX PE Ratio History or the PE ratio history for another stock, we hope our site will come to mind as your go-to PE ratio history research resource of choice.