Is Protagonist Therapeutics, Inc. overvalued or undervalued?

As of 17 October 2025, the valuation grade for Protagonist Therapeutics, Inc. moved from expensive to very expensive. The company appears to be overvalued based on its high valuation ratios, including a P/E ratio of 60, an EV to EBITDA of 94.50, and a Price to Book Value of 4.89. In comparison, Aurinia Pharmaceuticals, Inc. has a more reasonable P/E ratio of 20.87 and an EV to EBITDA of 12.92, indicating that Protagonist is trading at a significant premium relative to its peers.
Despite a strong year-to-date return of 100.78% compared to the S&P 500's 13.30%, the high valuation metrics suggest that the stock may not be sustainable at its current levels. The substantial disparity in valuation ratios, particularly when compared to its peers, reinforces the conclusion that Protagonist Therapeutics is overvalued.