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, indicating a significant increase in perceived overvaluation. The company is 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 of 20.87 and an EV to EBITDA of 12.92, highlighting the disparity in valuation within the sector.
Despite the company's impressive returns, such as a 100.78% year-to-date return compared to the S&P 500's 13.30%, the high valuation metrics suggest that Protagonist Therapeutics, Inc. may not sustain such performance in the long term. Overall, the company's current valuation appears unsustainable given the substantial premiums over its peers.