Protagonist Therapeutics Inc
NASDAQ: PTGX · HEALTHCARE · BIOTECHNOLOGY
Updated 2026-09-11
Protagonist Therapeutics Inc (PTGX) Stock Valuation Analysis
Fair value estimate, historical valuation range, and quality signals for PTGX.
Valued
Valuation reasonably reflects current fundamentals. Limited margin of safety at these levels.
PTGX historical valuation range
Where current P/E sits in PTGX's own 5Y range.
PTGX intrinsic value (DCF)
DCF-based fair value estimate vs current market price.
Standard discounted cash flow models produce unreliable output for unprofitable or near-breakeven companies. Revenue-based multiples such as P/S and EV/Sales, combined with the historical valuation position above, give a more reliable read for this stock.
Intrinsic value calculated using discounted cash flow (DCF) model based on projected free cash flows, discount rate, and terminal growth assumptions. A positive margin of safety indicates the current price is below estimated fair value, providing a cushion against estimation error.
PTGX valuation signals
Quick-read green flags, caution flags, and risks based on current metrics.
P/E Ratio — History
Current: 140.86x
P/S Ratio — History
Current: 33.29x
Is PTGX overvalued in 2026?
Protagonist Therapeutics Inc (PTGX) currently trades at $148.18 per share with a market capitalization of $9,388,525,000.00. Based on our multi-factor framework, the stock trades at a fair valuation with a Smart Value Score of 63/100. This score blends growth quality, financial health, and price attractiveness into a single institutional-grade read.
The stock trades at a P/E ratio of 140.9x, above its 5-year median of 71.7x.
Looking at its own history, PTGX is currently trading more expensive than 90% of the last 5Y on P/E. This places it in the 90th percentile of its historical range, a zone where forward returns have typically been muted.
A standard DCF model does not produce reliable output for PTGX under current conditions. For unprofitable or near-breakeven companies, revenue-based multiples such as EV/Sales and historical P/S percentile are more informative than intrinsic value calculations.
Financial quality is a concern. The Piotroski F-Score of 3/9 flags weakening fundamentals that deserve closer scrutiny before the valuation case can be fully trusted.
Bottom line: PTGX trades at a fair valuation on our framework, with a Smart Value Score of 63/100. The valuation is defensible but offers no obvious bargain. Patience or a better entry price may reward disciplined buyers.
Frequently asked questions
Is PTGX overvalued?
PTGX scores 63/100 on our Smart Value Score (Grade C+), a mixed overall profile. A standard DCF is unreliable here given the profitability profile, so valuation leans on revenue-based measures like EV/Sales and the P/S percentile below.
What is PTGX's fair value?
A standard DCF is unreliable for PTGX given its current profitability profile. Revenue-based approaches like EV/Sales or the historical P/S percentile are more informative for this stock.
What P/E ratio does PTGX trade at?
PTGX trades at a P/E of 140.9x on trailing twelve-month earnings, against a 5-year median of 71.7x. P/E is what you pay per dollar of profit, and sitting above its own median means the stock is pricier than usual relative to its earnings.
Is PTGX a buy based on valuation?
Our Smart Value rating for PTGX is Hold, from a Smart Value Score of 63/100 that blends growth, quality, and valuation. The profile is balanced and best suited to investors who already have a thesis. This is research to inform your decision, not personalized financial advice.
How does PTGX's valuation compare to its history?
On P/E, PTGX sits in the 90th percentile of its own 5Y range, historically expensive relative to where it has traded. A high percentile means today's multiple is near the top of its historical band.
What is PTGX's Smart Value Score?
PTGX's Smart Value Score is 63/100. It is a proprietary WallStSmart metric blending growth quality, financial health, and valuation into a single 0-100 read, and scores above 75 are rare, signaling strong multi-factor alignment.