On this page we presented the CSTL PE Ratio History information for Castle Biosciences' stock. The average CSTL 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 111.2. Meanwhile, using the trailing twelve month (TTM) quarterly earnings result as our method of calculation the "E" value at each measurement period, the average CSTL PE ratio history based on this TTM earnings result method is 78.7. Note: any PE calculations resulting in a value exceeding 500 were discarded as not meaningful. Note: any PE calculations involving negative earnings were discarded as not meaningful.

Let's now compare this CSTL PE ratio history result, against the recent PE: when this page was posted on 12/12/2025, the most recent closing price for CSTL had been 38.63, and the most recent quarterly earnings result, annualized, was 0.6. Meanwhile, the most recent TTM earnings summed to 0.25. From these numbers, we calculate the recent CSTL PE on 12/12/2025 based on annualized quarterly EPS was 64.4. Based on CSTL's history, that recent PE is low relative to the historical average, with the recent PE 42.1% lower than the historical average PE across our data set for Castle Biosciences. Looking at the recent CSTL PE on 12/12/2025 based on TTM EPS, we calculate the ratio at 154.5. Based on CSTL's history, that recent PE is elevated relative to the historical average, with the recent PE 96.3% higher than the historical average PE across our Castle Biosciences data set with TTM EPS used in the calculation at each period.

Another interesting CSTL PE ratio history calculation we look at is to take the median earnings per share of the last four quarters for CSTL, and then annualize the resulting value... with that annualized number then being used in the PE calculation. To walk through this math for CSTL, we start with the past four EPS numbers and we first sort them from lowest to highest: -0.20, -0.02, 0.15, and 0.32. We then toss out the highest and lowest result, and then take the average of those two middle numbers — -0.02 and 0.15 — which gives us the median of 0.07. Basically the way to think about this 0.07 number is this: for the trailing four earnings reports, 0.07 marks the "middle ground" number where CSTL has reported a value higher than 0.07 half the time, and has reported a value lower than 0.07 half the time. Annualizing that median value then gets us to 0.28/share, which we use as the denominator in our next PE calculation. With 38.63 as the numerator (as of 12/12/2025), the calculation is then 38.63 / 0.28 = 138.0 as the CSTL PE ratio as of 12/12/2025, based on that annualized median value we calculated.

For self directed investors doing their due diligence on CSTL or any other given stock, valuation analysis for CSTL 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 Castle Biosciences 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 CSTL. Thanks for visiting, and the next time you need to research CSTL 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.