Protagonist Therapeutics, Inc. (PTGX) P/E Ratio History
Historical price-to-earnings valuation from 2024 to 2025
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PTGX Valuation Context
How does the current P/E compare to historical and market benchmarks?
P/E Ratio Analysis
As of May 8, 2026, Protagonist Therapeutics, Inc. (PTGX) trades at a price-to-earnings ratio of -48.2x, with a stock price of $98.85 and trailing twelve-month earnings per share of $-1.63.
The current P/E is 212% below its 5-year average of 43.1x. Over the past five years, PTGX's P/E has ranged from a low of 9.2x to a high of 107.1x, placing the current valuation at the 0th percentile of its historical range.
Compared to the Healthcare sector median P/E of 22.3x, PTGX trades at a 316% discount to its sector peers. The sector includes 241 companies with P/E ratios ranging from 0.0x to 177.5x.
Relative to the broader market, PTGX trades at a notable discount to the S&P 500 median P/E of 25.1x. Investors should consider the company's growth prospects, competitive position, and earnings quality when evaluating whether the current valuation is justified.
For a comprehensive intrinsic value estimate using discounted cash flow analysis, see our PTGX DCF Valuation Calculator →
Note: P/E ratio is just one valuation metric. It does not account for balance sheet strength, cash flow quality, or growth sustainability. Always conduct comprehensive due diligence before making investment decisions.
PTGX P/E vs Peers
P/E ratio compared to closely matched public peers
| Company | Market Cap | P/E Ratio | PEG Ratio | EPS Growth (1Y) |
|---|---|---|---|---|
| $39B | 127.0Lowest | -Best | +207%Best |
Peers sorted by market capitalization. P/E below peers may indicate undervaluation or lower growth expectations. Consider PEG ratio for growth-adjusted comparison.
PTGX Historical P/E Data (2024–2025)
Quarterly P/E ratios calculated from closing price and TTM EPS
| Quarter | Date | Price | TTM EPS | P/E Ratio | vs Avg |
|---|---|---|---|---|---|
| FY2025 Q3 | $66.43 | $0.62 | 107.1x | +149% | |
| FY2025 Q2 | Mon Jun 30 2025 00:00:00 GM | $55.27 | $0.70 | 79.0x | +83% |
| FY2025 Q1 | Mon Mar 31 2025 00:00:00 GM | $48.36 | $0.75 | 64.5x | +50% |
| FY2024 Q4 | $38.60 | $4.20 | 9.2x | -79% | |
| FY2024 Q3 | Mon Sep 30 2024 00:00:00 GM | $45.00 | $2.66 | 16.9x | -61% |
| FY2024 Q2 | Sun Jun 30 2024 00:00:00 GM | $34.65 | $2.62 | 13.2x | -69% |
| FY2024 Q1 | Sun Mar 31 2024 00:00:00 GM | $28.93 | $2.44 | 11.9x | -72% |
Average P/E for displayed period: 43.1x
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Start ComparisonPTGX — Frequently Asked Questions
Quick answers to the most common questions about buying PTGX stock.
Is PTGX stock overvalued or undervalued?
PTGX trades at -48.2x P/E, below its 5-year average of 43.1x. At the N/A percentile of historical range, the stock is priced at a discount to its own history.
How does PTGX's valuation compare to peers?
Protagonist Therapeutics, Inc. P/E of -48.2x compares to sector median of 22.3x. The discount suggests lower growth expectations or higher risk.
What is PTGX's PEG ratio?
PTGX PEG ratio is N/A. Above 2.0 indicates premium valuation relative to growth rate. Historical P/E data spans 2024-2025.