Ionis Pharmaceuticals, Inc. (IONS) P/E Ratio History
Historical price-to-earnings valuation from 2009 to 2020
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IONS Valuation Context
How does the current P/E compare to historical and market benchmarks?
P/E Ratio Analysis
As of May 8, 2026, Ionis Pharmaceuticals, Inc. (IONS) trades at a price-to-earnings ratio of -31.9x, with a stock price of $76.02 and trailing twelve-month earnings per share of $-1.98.
The current P/E is 132% 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 22.3x, IONS trades at a 243% 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, IONS 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 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 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 | 127.0 | -Best | +207%Best | |
| $10B | 30.1Lowest | -Best | -19% |
Peers sorted by market capitalization. P/E below peers may indicate undervaluation or lower growth expectations. Consider PEG ratio for growth-adjusted comparison.
IONS Historical P/E Data (2009–2020)
Quarterly P/E ratios calculated from closing price and TTM EPS
| Quarter | Date | Price | TTM EPS | P/E Ratio | vs Avg |
|---|---|---|---|---|---|
| FY2020 Q3 | Wed Sep 30 2020 00:00:00 GM | $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 | Mon Sep 30 2019 00:00:00 GM | $59.91 | $3.00 | 20.0x | -80% |
| FY2019 Q2 | Sun Jun 30 2019 00:00:00 GM | $64.27 | $2.79 | 23.0x | -77% |
| FY2019 Q1 | Sun Mar 31 2019 00:00:00 GM | $81.17 | $2.49 | 32.6x | -67% |
| FY2018 Q4 | Mon Dec 31 2018 00:00:00 GM | $54.06 | $1.86 | 29.1x | -71% |
| FY2017 Q3 | Sat Sep 30 2017 00:00:00 GM | $50.70 | $0.18 | 278.9x | +179% |
| FY2017 Q2 | Fri Jun 30 2017 00:00:00 GM | $50.87 | $0.25 | 203.8x | +104% |
| FY2015 Q3 | Wed Sep 30 2015 00:00:00 GM | $40.42 | $0.10 | 404.2x | +304% |
| FY2015 Q2 | $57.55 | $0.17 | 338.5x | +238% |
Average P/E for displayed period: 100.0x
Full IONS Stock Analysis
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Start ComparisonIONS — Frequently Asked Questions
Quick answers to the most common questions about buying IONS stock.
Is IONS stock overvalued or undervalued?
IONS trades at -31.9x P/E, below its 5-year average of 100.0x. At the N/A percentile of historical range, the stock is priced at a discount to its own history.
How does IONS's valuation compare to peers?
Ionis Pharmaceuticals, Inc. P/E of -31.9x compares to sector median of 22.3x. The discount suggests lower growth expectations or higher risk.
What is IONS's PEG ratio?
IONS PEG ratio is N/A. Above 2.0 indicates premium valuation relative to growth rate. Historical P/E data spans 2009-2020.