Protagonist Therapeutics, Inc. (PTGX) P/E Ratio History
Deep ValueTrading at -58.0x · 0th percentile of 5-year range · Significant discount to historical valuation · Data 2024–2025
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P/E Ratio Analysis
As of June 24, 2026, Protagonist Therapeutics, Inc. (PTGX) trades at a price-to-earnings ratio of -58.0x, with a stock price of $118.96 and trailing twelve-month earnings per share of $-1.63.
The current P/E is 235% 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 22.0x, PTGX trades at a 363% discount to its sector peers. The sector includes 233 companies with P/E ratios ranging from 0.0x to 196.5x.
Relative to the broader market, PTGX trades at a notable discount to the S&P 500 median P/E of 24.6x. 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 Cross-Benchmark Valuation
How does the current P/E compare to sector peers and the broader market?
PTGX P/E vs Peers
Immunology and Inflammation Therapies peers sorted by market cap
| Company | Market Cap | P/E Ratio | PEG Ratio | EPS Growth (1Y) |
|---|---|---|---|---|
| $38B | 123.7Lowest | -Best | +207%Best |
Lower P/E can signal a discount or weaker growth expectations; PEG adds growth context.
PTGX Historical P/E Data (2024–2025)
Quarterly P/E ratios calculated from closing price and TTM EPS
| Quarter | Period End | Price | TTM EPS | P/E Ratio | vs Avg |
|---|---|---|---|---|---|
| FY2025 Q3 | - | $66.43 | $0.62 | 107.1x | +149% |
| FY2025 Q2 | Jun 30 2025 | $55.27 | $0.70 | 79.0x | +83% |
| FY2025 Q1 | Mar 31 2025 | $48.36 | $0.75 | 64.5x | +50% |
| FY2024 Q4 | - | $38.60 | $4.20 | 9.2x | -79% |
| FY2024 Q3 | Sep 30 2024 | $45.00 | $2.66 | 16.9x | -61% |
| FY2024 Q2 | Jun 30 2024 | $34.65 | $2.62 | 13.2x | -69% |
| FY2024 Q1 | Mar 31 2024 | $28.93 | $2.44 | 11.9x | -72% |
Average P/E for displayed period: 43.1x
Intrinsic Valuation
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Historical Returns
2+ years return with dividends reinvested.
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Peer Comparison
Compare growth, multiples, and margins vs sector.
PTGX — Frequently Asked Questions
Quick answers to the most common questions about buying PTGX stock.
What is PTGX's P/E ratio?
Protagonist Therapeutics, Inc. (PTGX) trailing twelve-month P/E ratio is -58.0x, based on TTM diluted EPS of $-1.63. The 5-year average P/E is 43.1x and the historical range spans 9.2x to 107.1x.
Is PTGX stock overvalued or undervalued?
PTGX trades at -58.0x P/E, below its 5-year average of 43.1x. At the 0th percentile of its historical range (9.2x–107.1x), the stock is priced at a discount to its own history.
Is PTGX stock expensive?
No, PTGX is not expensive on a historical basis. The current P/E of -58.0x is below the 5-year average of 43.1x and sits at the 0th percentile of its valuation range.
What is PTGX's historical P/E range?
Over the past 5 years, PTGX's P/E ratio has ranged from 9.2x to 107.1x, with a median of 16.9x and an average of 43.1x. The current P/E of -58.0x places the stock at the 0th percentile of this range. Full historical data spans 2024–2025.
How does PTGX's P/E compare to the S&P 500?
PTGX trades at -58.0x P/E versus the S&P 500 median of 24.6x. The 336% discount to the market suggests lower growth expectations or perceived higher risk.
How does PTGX's valuation compare to Healthcare peers?
Protagonist Therapeutics, Inc. P/E of -58.0x compares to the Healthcare sector median of 22.0x. The discount suggests lower growth expectations, weaker margins, or higher perceived risk relative to peers. See the peer comparison table on this page for ticker-by-ticker P/E and PEG.
What is PTGX's PEG ratio?
PTGX PEG ratio is N/A, based on a P/E of -58.0x and EPS growth of -148.5%. PEG normalises P/E by growth and helps compare stocks with different earnings trajectories.
What is PTGX's earnings yield?
PTGX earnings yield is N/A, the inverse of its -58.0x P/E ratio. Earnings yield represents the percentage of each dollar invested that the company earns. It can be compared directly to bond yields to assess relative attractiveness of stocks versus fixed income.