Ionis Pharmaceuticals, Inc. (IONS) P/E Ratio History
Deep ValueTrading at -31.1x · 0th percentile of 5-year range · Significant discount to historical valuation · Data 2009–2020
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P/E Ratio Analysis
As of June 22, 2026, Ionis Pharmaceuticals, Inc. (IONS) trades at a price-to-earnings ratio of -31.1x, with a stock price of $74.12 and trailing twelve-month earnings per share of $-1.98.
The current P/E is 131% below its 5-year average of 100.0x. Over the past five years, IONS's P/E has ranged from a low of 6.4x to a high of 404.2x, placing the current valuation at the 0th percentile of its historical range.
Compared to the Healthcare sector median P/E of 22.1x, IONS trades at a 241% discount to its sector peers. The sector includes 234 companies with P/E ratios ranging from 0.0x to 197.0x.
Relative to the broader market, IONS trades at a notable discount to the S&P 500 median P/E of 24.4x. 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 IONS 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.
IONS Cross-Benchmark Valuation
How does the current P/E compare to sector peers and the broader market?
IONS P/E vs Peers
RNA and Genome Editing Developers peers sorted by market cap
| Company | Market Cap | P/E Ratio | PEG Ratio | EPS Growth (1Y) |
|---|---|---|---|---|
| $37B | 119.4 | -Best | +207%Best | |
| $11B | 30.4Lowest | -Best | -19% |
Lower P/E can signal a discount or weaker growth expectations; PEG adds growth context.
IONS Historical P/E Data (2009–2020)
Quarterly P/E ratios calculated from closing price and TTM EPS
| Quarter | Period End | Price | TTM EPS | P/E Ratio | vs Avg |
|---|---|---|---|---|---|
| FY2020 Q3 | Sep 30 2020 | $47.45 | $0.48 | 98.9x | -1% |
| FY2020 Q2 | - | $58.96 | $0.88 | 67.0x | -33% |
| FY2020 Q1 | - | $47.28 | $1.10 | 42.9x | -57% |
| FY2019 Q4 | - | $60.41 | $2.07 | 29.1x | -71% |
| FY2019 Q3 | Sep 30 2019 | $59.91 | $3.00 | 20.0x | -80% |
| FY2019 Q2 | Jun 30 2019 | $64.27 | $2.79 | 23.0x | -77% |
| FY2019 Q1 | Mar 31 2019 | $81.17 | $2.49 | 32.6x | -67% |
| FY2018 Q4 | Dec 31 2018 | $54.06 | $1.86 | 29.1x | -71% |
| FY2017 Q3 | Sep 30 2017 | $50.70 | $0.18 | 278.9x | +179% |
| FY2017 Q2 | Jun 30 2017 | $50.87 | $0.25 | 203.8x | +104% |
| FY2015 Q3 | Sep 30 2015 | $40.42 | $0.10 | 404.2x | +304% |
| FY2015 Q2 | - | $57.55 | $0.17 | 338.5x | +238% |
| FY2009 Q4 | - | $11.11 | $1.74 | 6.4x | -94% |
| FY2009 Q3 | Sep 30 2009 | $14.57 | $1.72 | 8.5x | -92% |
| FY2009 Q2 | - | $16.50 | $1.81 | 9.1x | -91% |
| FY2009 Q1 | - | $15.01 | $1.82 | 8.3x | -92% |
Average P/E for displayed period: 100.0x
Full Stock Analysis
Deep dive into IONS consensus models and risk factors.
Intrinsic Valuation
DCF models, multiple analysis, and analyst estimates.
Historical Returns
17+ years return with dividends reinvested.
DCA Calculator
See how regular investing compounds over time.
Peer Comparison
Compare growth, multiples, and margins vs sector.
IONS — Frequently Asked Questions
Quick answers to the most common questions about buying IONS stock.
What is IONS's P/E ratio?
Ionis Pharmaceuticals, Inc. (IONS) trailing twelve-month P/E ratio is -31.1x, based on TTM diluted EPS of $-1.98. The 5-year average P/E is 100.0x and the historical range spans 6.4x to 404.2x.
Is IONS stock overvalued or undervalued?
IONS trades at -31.1x P/E, below its 5-year average of 100.0x. At the 0th percentile of its historical range (6.4x–404.2x), the stock is priced at a discount to its own history.
Is IONS stock expensive?
No, IONS is not expensive on a historical basis. The current P/E of -31.1x is below the 5-year average of 100.0x and sits at the 0th percentile of its valuation range.
What is IONS's historical P/E range?
Over the past 5 years, IONS's P/E ratio has ranged from 6.4x to 404.2x, with a median of 32.6x and an average of 100.0x. The current P/E of -31.1x places the stock at the 0th percentile of this range. Full historical data spans 2009–2020.
How does IONS's P/E compare to the S&P 500?
IONS trades at -31.1x P/E versus the S&P 500 median of 24.4x. The 227% discount to the market suggests lower growth expectations or perceived higher risk.
How does IONS's valuation compare to Healthcare peers?
Ionis Pharmaceuticals, Inc. P/E of -31.1x compares to the Healthcare sector median of 22.1x. 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 IONS's PEG ratio?
IONS PEG ratio is N/A, based on a P/E of -31.1x and EPS growth of 21.7%. PEG normalises P/E by growth and helps compare stocks with different earnings trajectories.
What is IONS's earnings yield?
IONS earnings yield is N/A, the inverse of its -31.1x 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.