Comprehensive Stock Comparison
Compare Ionis Pharmaceuticals, Inc. (IONS) vs Regeneron Pharmaceuticals, Inc. (REGN) Stock
Analyze side-by-side fundamentals, valuation, growth, and profitability to decide which stock is the better buy.
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Quick Verdict
| Category | Winner | Why |
|---|---|---|
| Growth | IONS | 33.9% revenue growth vs REGN's 1.0% |
| Quality / Margins | REGN | 31.4% net margin vs IONS's -40.4% |
| Stability / Safety | REGN | Beta 0.58 vs IONS's 0.68, lower leverage |
| Dividends | REGN | 0.4% yield; 1-year raise streak; IONS pays no meaningful dividend |
| Momentum (1Y) | IONS | +144.5% vs REGN's +12.4% |
| Efficiency (ROA) | REGN | 11.1% ROA vs IONS's -10.8%, ROIC 12.4% vs -12.2% |
Who Each Stock Is For
Income & stability
Growth exposure
Long-term compounding (10Y)
Sleep-well-at-night portfolio
Defensive / Recession hedge
Business Model
What each company does and how it makes money
Ionis Pharmaceuticals is a biotech company that discovers and develops RNA-targeted therapeutics for rare diseases and other serious conditions. It generates revenue primarily through royalties from partnered drugs like SPINRAZA for spinal muscular atrophy — which contributed over 70% of total revenue in recent years — plus milestone payments and research funding from pharmaceutical partners. Its key competitive advantage is its proprietary antisense technology platform, which enables precise targeting of disease-causing RNA and has produced multiple FDA-approved therapies.
Regeneron Pharmaceuticals is a biotechnology company that discovers, develops, and commercializes innovative medicines for serious diseases. It generates revenue primarily from sales of its flagship products — EYLEA for eye diseases (~60% of revenue) and Dupixent for inflammatory conditions (~30%) — with additional income from collaborations and royalties. The company's competitive advantage lies in its proprietary VelocImmune technology platform for creating human antibodies and its deep expertise in genetic research, which enables rapid drug discovery and development.
Revenue Breakdown by Segment
How each company's revenue is distributed across its business units
Financial Metrics Comparison
Side-by-side fundamentals across 2 stocks. BestLagging
Financial Scorecard
REGN leads in 4 of 6 categories (Financial Metrics, Valuation Metrics). IONS leads in 1 (Total Returns).
Financial Metrics (TTM)
REGN is the larger business by revenue, generating $14.3B annually — 15.2x IONS's $943M. REGN is the more profitable business, keeping 31.4% of every revenue dollar as net income compared to IONS's -40.4%. On growth, REGN holds the edge at +2.5% YoY revenue growth, suggesting stronger near-term business momentum.
| Metric | IONSIonis Pharmaceuti… | REGNRegeneron Pharmac… |
|---|---|---|
| RevenueTrailing 12 months | $943M | $14.3B |
| EBITDAEarnings before interest/tax | -$367M | $4.2B |
| Net IncomeAfter-tax profit | -$381M | $4.5B |
| Free Cash FlowCash after capex | $162.9B | $3.2B |
| Gross MarginGross profit ÷ Revenue | +98.3% | +86.3% |
| Operating MarginEBIT ÷ Revenue | -40.5% | +25.7% |
| Net MarginNet income ÷ Revenue | -40.4% | +31.4% |
| FCF MarginFCF ÷ Revenue | +172.6% | +22.0% |
| Rev. Growth (YoY)Latest quarter vs prior year | -10.4% | +2.5% |
| EPS Growth (YoY)Latest quarter vs prior year | -113.6% | -2.5% |
Valuation Metrics
| Metric | IONSIonis Pharmaceuti… | REGNRegeneron Pharmac… |
|---|---|---|
| Market CapShares × price | $13.3B | $107.6B |
| Enterprise ValueMkt cap + debt − cash | $15.7B | $91.4B |
| Trailing P/EPrice ÷ TTM EPS | -34.10x | 18.84x |
| Forward P/EPrice ÷ next-FY EPS est. | — | 17.25x |
| PEG RatioP/E ÷ EPS growth rate | — | 2.98x |
| EV / EBITDAEnterprise value multiple | — | 21.64x |
| Price / SalesMarket cap ÷ Revenue | 14.04x | 7.50x |
| Price / BookPrice ÷ Book value/share | 26.55x | 2.72x |
| Price / FCFMarket cap ÷ FCF | — | 26.36x |
Profitability & Efficiency
REGN delivers a 14.4% return on equity — every $100 of shareholder capital generates $14 in annual profit, vs $-78 for IONS. REGN carries lower financial leverage with a 0.09x debt-to-equity ratio, signaling a more conservative balance sheet compared to IONS's 5.78x. On the Piotroski fundamental quality scale (0–9), REGN scores 7/9 vs IONS's 3/9, reflecting strong financial health.
| Metric | IONSIonis Pharmaceuti… | REGNRegeneron Pharmac… |
|---|---|---|
| ROE (TTM)Return on equity | -77.9% | +14.4% |
| ROA (TTM)Return on assets | -10.8% | +11.1% |
| ROICReturn on invested capital | -12.2% | +12.4% |
| ROCEReturn on capital employed | -16.3% | +10.8% |
| Piotroski ScoreFundamental quality 0–9 | 3 | 7 |
| Debt / EquityFinancial leverage | 5.78x | 0.09x |
| Net DebtTotal debt minus cash | $2.5B | -$16.2B |
| Cash & Equiv.Liquid assets | $372M | $18.9B |
| Total DebtShort + long-term debt | $2.8B | $2.7B |
| Interest CoverageEBIT ÷ Interest expense | -3.53x | 120.42x |
Total Returns (with DRIP)
A $10,000 investment in REGN five years ago would be worth $16,977 today (with dividends reinvested), compared to $15,014 for IONS. Over the past 12 months, IONS leads with a +144.5% total return vs REGN's +12.4%. The 3-year compound annual growth rate (CAGR) favors IONS at 31.2% vs REGN's 1.1% — a key indicator of consistent wealth creation.
| Metric | IONSIonis Pharmaceuti… | REGNRegeneron Pharmac… |
|---|---|---|
| YTD ReturnYear-to-date | +1.9% | +0.8% |
| 1-Year ReturnPast 12 months | +144.5% | +12.4% |
| 3-Year ReturnCumulative with dividends | +126.0% | +3.4% |
| 5-Year ReturnCumulative with dividends | +50.1% | +69.8% |
| 10-Year ReturnCumulative with dividends | +134.8% | +104.7% |
| CAGR (3Y)Annualised 3-year return | +31.2% | +1.1% |
Risk & Volatility
REGN is the less volatile stock with a 0.58 beta — it tends to amplify market swings less than IONS's 0.68 beta. A beta below 1.0 means the stock typically moves less than the S&P 500.
| Metric | IONSIonis Pharmaceuti… | REGNRegeneron Pharmac… |
|---|---|---|
| Beta (5Y)Sensitivity to S&P 500 | 0.68x | 0.58x |
| 52-Week HighHighest price in past year | $86.74 | $821.11 |
| 52-Week LowLowest price in past year | $23.95 | $476.49 |
| % of 52W HighCurrent price vs 52-week peak | +93.6% | +95.2% |
| RSI (14)Momentum oscillator 0–100 | 44.7 | 49.1 |
| Avg Volume (50D)Average daily shares traded | 1.7M | 687K |
Analyst Outlook
Wall Street rates IONS as "Buy" and REGN as "Buy". Consensus price targets imply 9.8% upside for IONS (target: $89) vs 9.7% for REGN (target: $857). REGN is the only dividend payer here at 0.44% yield — a key consideration for income-focused portfolios.
| Metric | IONSIonis Pharmaceuti… | REGNRegeneron Pharmac… |
|---|---|---|
| Analyst RatingConsensus buy/hold/sell | Buy | Buy |
| Price TargetConsensus 12-month target | $89.13 | $857.17 |
| # AnalystsCovering analysts | 32 | 48 |
| Dividend YieldAnnual dividend ÷ price | — | +0.4% |
| Dividend StreakConsecutive years of raises | — | 1 |
| Dividend / ShareAnnual DPS | — | $3.41 |
| Buyback YieldShare repurchases ÷ mkt cap | 0.0% | +3.2% |
Historical Charts
Charts are rendered on first load. Hover for details.
Chart 1Total Return — 5 Years (Rebased to 100)
| Stock | Mar 20 | Feb 26 | Change |
|---|---|---|---|
| Ionis Pharmaceutica… (IONS) | 100 | 158.83 | +58.8% |
| Regeneron Pharmaceu… (REGN) | 100 | 162.46 | +62.5% |
Regeneron Pharmaceu… (REGN) returned +70% over 5 years vs Ionis Pharmaceutica… (IONS)'s +50%. A $10,000 investment in REGN 5 years ago would be worth $16,977 today (including dividends reinvested).
Chart 2Revenue Growth — 10 Years
| Stock | 2016 | 2025 | Change |
|---|---|---|---|
| Ionis Pharmaceutica… (IONS) | $373M | $944M | +153.2% |
| Regeneron Pharmaceu… (REGN) | $4.9B | $14.3B | +195.1% |
Ionis Pharmaceuticals, Inc.'s revenue grew from $373M (2016) to $944M (2025) — a 10.9% CAGR. Regeneron Pharmaceuticals, Inc.'s revenue grew from $4.9B (2016) to $14.3B (2025) — a 12.8% CAGR.
Chart 3Net Margin Trend — 10 Years
| Stock | 2016 | 2025 | Change |
|---|---|---|---|
| Ionis Pharmaceutica… (IONS) | -16.2% | -40.4% | -149.1% |
| Regeneron Pharmaceu… (REGN) | 18.4% | 31.4% | +70.5% |
Ionis Pharmaceuticals, Inc.'s net margin went from -16% (2016) to -40% (2025). Regeneron Pharmaceuticals, Inc.'s net margin went from 18% (2016) to 31% (2025).
Chart 4P/E Ratio History — 9 Years
| Stock | 2017 | 2025 | Change |
|---|---|---|---|
| Regeneron Pharmaceu… (REGN) | 36.4 | 18.6 | -48.9% |
Regeneron Pharmaceuticals, Inc. has traded in a 9x–36x P/E range over 9 years; current trailing P/E is ~19x.
Chart 5EPS Growth — 10 Years
| Stock | 2016 | 2025 | Change |
|---|---|---|---|
| Ionis Pharmaceutica… (IONS) | -0.72 | -2.38 | -230.6% |
| Regeneron Pharmaceu… (REGN) | 7.7 | 41.48 | +438.7% |
Ionis Pharmaceuticals, Inc.'s EPS grew from $-0.72 (2016) to $-2.38 (2025). Regeneron Pharmaceuticals, Inc.'s EPS grew from $7.70 (2016) to $41.48 (2025) — a 21% CAGR.
Chart 6Free Cash Flow — 5 Years
Ionis Pharmaceuticals, Inc. generated $-320M FCF in 2025 (-2581% vs 2021). Regeneron Pharmaceuticals, Inc. generated $4B FCF in 2025 (-38% vs 2021).
IONS vs REGN: Frequently Asked Questions
8 questions · data-driven answers · updated daily
01Is IONS or REGN a better buy right now?
Regeneron Pharmaceuticals, Inc. (REGN) offers the better valuation at 18.8x trailing P/E (17.3x forward), making it the more compelling value choice. Analysts rate Ionis Pharmaceuticals, Inc. (IONS) a "Buy" — based on 32 analyst ratings — the highest consensus in this comparison. The "better buy" depends entirely on your goals: growth investors should weight revenue trajectory, value investors should weight P/E and PEG, and income investors should weight dividend yield and streak.
02Which is the better long-term investment — IONS or REGN?
Over the past 5 years, Regeneron Pharmaceuticals, Inc. (REGN) delivered a total return of +69.8%, compared to +50.1% for Ionis Pharmaceuticals, Inc. (IONS). A $10,000 investment in REGN five years ago would be worth approximately $17K today (assuming dividends reinvested). Over 10 years, the gap is even starker: IONS returned +134.8% versus REGN's +104.7%. Past returns do not guarantee future results, and the stock with the higher historical return may already have its best growth priced in.
03Which is safer — IONS or REGN?
By beta (market sensitivity over 5 years), Regeneron Pharmaceuticals, Inc. (REGN) is the lower-risk stock at 0.58β versus Ionis Pharmaceuticals, Inc.'s 0.68β — meaning IONS is approximately 18% more volatile than REGN relative to the S&P 500. On balance sheet safety, Regeneron Pharmaceuticals, Inc. (REGN) carries a lower debt/equity ratio of 9% versus 6% for Ionis Pharmaceuticals, Inc. — giving it more financial flexibility in a downturn.
04Which has better profit margins — IONS or REGN?
Regeneron Pharmaceuticals, Inc. (REGN) is the more profitable company, earning 31.4% net margin versus -40.4% for Ionis Pharmaceuticals, Inc. — meaning it keeps 31.4% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: REGN leads at 25.7% versus -40.5% for IONS. At the gross margin level — before operating expenses — IONS leads at 98.3%, reflecting greater pricing power or product mix advantage. Stronger margins indicate durable pricing power, lower cost of revenue, or higher mix of software/services. They are one of the clearest signs of business quality.
05Is IONS or REGN more undervalued right now?
Analyst consensus price targets imply the most upside for IONS: 9.8% to $89.13.
06Which pays a better dividend — IONS or REGN?
In this comparison, REGN (0.4% yield) pays a dividend. IONS does not pay a meaningful dividend and should not be held primarily for income.
07Is IONS or REGN better for a retirement portfolio?
For long-horizon retirement investors, Regeneron Pharmaceuticals, Inc. (REGN) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0.58), +104.7% 10Y return). Both have compounded well over 10 years (REGN: +104.7%, IONS: +134.8%), confirming both are viable long-term holds — but the lower-volatility option typically results in less emotional selling during corrections. Retirement portfolios generally favour predictability over maximum returns. Consult a financial advisor before making allocation decisions.
08What are the main differences between IONS and REGN?
Both stocks operate in the Healthcare sector, making this a peer-level intra-sector comparison — the same macro tailwinds and headwinds will affect both. These fundamental differences mean investors should not choose between them on a single metric — the "better stock" depends entirely on which of these characteristics aligns with your investment strategy.
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