Regeneron Pharmaceuticals Inc (REGN) stock analysis
Regeneron Pharmaceuticals Inc (REGN) clears 8 of this site's 8 mechanical value filters, 6 of 8 Buffett-style checks and 4 of 5 Lynch-style checks. At $819.09 it trades 35.9% above this site's neutral DCF value (a margin of safety of -35.9%). Its earnings quality rates Strong and it returns +3.4% to shareholders net of dilution. Figures are as of October 23, 2026, from SEC filings and market data refreshed weekly; this is educational analysis, not investment advice.
Data as of October 23, 2026. Refreshed weekly from SEC filings and market data.
What does Regeneron do?
Regeneron is a biotech company that discovers and sells antibody drugs. Its largest products treat eye disease (Eylea) and inflammatory conditions such as eczema and asthma (Dupixent, developed with Sanofi).
Brands and businesses it owns
- Eylea
- Dupixent (with Sanofi)
- Libtayo
- Praluent
What stands out about Regeneron?
- The share price implies 15.8% yearly growth. At $819.09, REGN's free cash flow of $35.30 per share would have to grow 15.8% a year, fading to 2.5% by year 10, for this site's DCF (10% discount rate) to match the price. This site's baseline starts at 8%, so the price asks for more growth than the baseline. Change the assumptions.
- No filter fails. REGN passes 8 of the 8 value filters. See every filter.
- The margin of safety is falling. It went from -23% on Oct 7 to -36% on Oct 23 across 5 weekly readings. See the trend.
- Strongest against peers: net margin. At 27.9% (peer median 16.2%) it ranks 3rd of 15 among pharma & biotech stocks this site tracks. See the ranking.
- Weakest against peers: dividend yield. At 0.46% (peer median 2.38%) it ranks 11th of 11 among pharma & biotech stocks this site tracks. See the ranking.
How has Regeneron's share price moved?
The interactive price chart needs JavaScript.
Is Regeneron undervalued? The value diligence check
Every value-investing signal this site computes for this stock, gathered in one place: the same real numbers from the tools below, not a new score.
- Margin of safety (DCF) -35.9%
- P/E vs. its own history 19.2x · the middle Real range: 8.8x–25.3x over 5 years (net income per diluted share from each fiscal year's 10-K, paired with the real closing price at that fiscal year-end).
- Wall St. analyst rating Buy · 3.92/5 37 analysts this month: 8 strong buy, 18 buy, 11 hold, 0 sell, 0 strong sell (Finnhub). Up from 3.89 last month.
- Altman Z″-Score (bankruptcy risk) 9.21 · Safe zone
- Earnings quality (is the profit real?) Strong · 1 watch Beneish M-score −2.55 · accruals −1.2% of assets · 109% of profit arrived as cash · stock comp 6.9% of revenue · share count −2.3% a year. From the latest 10-K (year to Dec 2025) - see the Earnings Quality Screener for how each check is scored.
- Shareholder yield (cash back to owners) +3.4% net Latest fiscal year (2025): dividends 0.4% + buybacks 4.1% − stock comp 1.2%, as a share of today's market cap. Over 14 years its split-adjusted share count rose 20%. See Shareholder Yield Leaders.
- Capital needed to grow (See's test) $3.78 per $1 of new profit · Capital-hungry Operating profit $2.0B → $3.9B, capital needed $4.0B → $11B, 2016–2025 (3-year averages); return on capital now 35% before tax. Buffett's See's Candies needed $0.42 per $1 of new profit, FlightSafety $3.20, a typical grower about $5. See Capital-Light Compounders.
- PEG (growth at a reasonable price) 1.04 · About fair P/E 19.2× ÷ 18.4% a year of growth behind it. 97th lowest of 447 stocks with a usable PEG. Lynch's fair value is a PEG of 1; a very high PEG usually means almost no growth, a very low one a profit spike. See PEG Ratio Ranking.
- Compounder lenses (4) 3 of 4 · misses capital-light Capital-light growth: not cleared (profit grew 2.0×, under 2×); Profit is real: cleared; Cash to owners: cleared; Fair price (PEG): cleared. See Compounders at a Fair Price, which also lets you move the PEG bar.
- Value trap check Clear
- Munger's Inversion Check 0 flags
- Standing vs. sector peers 4 of 7 measures above the median Compared with the 14 other pharma & biotech stocks this site tracks: 4 in the top third, 1 in the bottom third.
- Dividend payout sustainability 0/6 · clean
How does Regeneron compare with its peers?
4 of 7 measures sit above the median of the 14 other pharma & biotech stocks tracked here, 4 in the top third and 1 in the bottom third.
- P/E ratiolower is cheaper · peer median 35.0× 19.2× ✓4th of 12
- Free-cash-flow yieldhigher is cheaper · peer median 4.5% 4.3% –9th of 15
- Return on equityhigher is better · peer median 23% 14% –9th of 15
- Net marginhigher is better · peer median 16.2% 27.9% ✓3rd of 15
- Revenue growthhigher is better, year on year · peer median 5.5% 9.3% ✓5th of 15
- Debt / equitylower is safer · peer median 0.94 0.09 ✓3rd of 15
- Dividend yieldamong dividend payers · peer median 2.38% 0.46% ✕11th of 11
Peers are the stocks this site tracks in the same sector group, not every listed competitor. The bar runs from the weakest peer (left) to the strongest (right); the tick is the middle. Measures that don't apply to a sector (cash-flow yield for banks, debt for financials) are left out.
What would Buffett & Lynch say?
Buffett's checklist is built around durable, profitable businesses bought at sensible prices, and REGN doesn't clear enough of it yet. In its favor: REGN is currently earning a strong return on shareholders' equity, and has kept that profitability up over five years, not just this year, carries a conservative amount of debt relative to equity, converts sales into profit at healthy margins, earns many times its interest expense, so debt service isn't a worry, and trades at a reasonable multiple of owner earnings, his own term for the real cash a business could pay out. Where it comes up short: REGN hasn't grown earnings per share fast enough over five years to impress him, and is trading above what a conservative discounted-cash-flow estimate says it's worth right now.
- ROE (TTM) > 11% ✓
- ROE (5yr avg) > 11% ✓
- Debt/Equity < 0.5 ✓
- Pretax margin > 15% ✓
- EPS growth (5yr) > 7% ✕
- Interest coverage > 5x ✓
- Trading below intrinsic value (DCF) ✕
- Price vs. owner earnings < 25x ✓
- Bonus: returning capital via buybacks FY2025
Lynch looked for growth stories that weren't overpriced for that growth, and REGN falls short of his bar. In its favor: REGN is growing at the modest, GDP-ish pace typical of a slow grower, isn't over-leveraged for a company of its type, is cheap enough for a business with limited growth ahead of it, and converts earnings into real cash at a reasonable price. Where it comes up short: REGN doesn't pay much of a dividend, which is the main reason to own a slow grower in the first place.
- Dividend yield > 2.5% ✕
- EPS growth 0%-10% ✓
- Debt/Equity < 0.6 ✓
- P/E < 20 ✓
- Price/FCF < 25 ✓
Quantitative approximations of each investor's documented approach, not endorsed by either investor or their estates - commentary, not this site's actual ranking criteria. Buffett never published a numeric checklist: only 2 of his 8 checks here trace to his own documented concepts ("owner earnings," from his 1986 shareholder letter, and "price is what you pay, value is what you get," his case against fixed P/E/P/B ceilings) - the other 6 (ROE, debt, margins, growth, interest coverage) use commonly-cited thresholds that are not numbers he himself published. The 8 hard filters below (plus the Munger check and Graham margin of safety) are this site's real, mechanical screen and are computed completely independently of the checklists above.
Berkshire Hathaway's own filing
Which of the 8 value filters does Regeneron pass?
- Market Cap > $25B $82.9B
- Trailing P/E < 25 19.16
- PEG Ratio < 1.5 1.04
- Price/Book < 8 2.62
- Price/Sales < 7 5.34
- EPS Growth YoY > -5% -4.5%
- vs 50-day MA (±12%) +3.5%
- vs 200-day MA (±12%) +11.3%
What is Regeneron's margin of safety?
-23% on 2026-10-07 → -36% on 2026-10-23 (5 weekly readings).
Where is Regeneron in its 52-week range?
What is the short interest in Regeneron?
2,150,303 shares short as of 2026-09-30 (FINRA settlement date). Reported twice a month, so this only changes roughly every two weeks, not daily.
What could go wrong with Regeneron? Munger's inversion check
"Invert, always invert." Instead of reasons to buy, these are reasons to hesitate, not a verdict, and not everything worth knowing about a business.
- Margin of safety, even in the bull case +20%
- Short interest under 5% of float 2.2%
- Passes most of the 6 fundamental filters 6/6 passed
- Price run-up backed by value, not just momentum +47% off 52wk low
- Debt/equity stable since 2019 0.00 → 0.06
Doesn't cover circle of competence, management quality, or accounting concerns: those need judgment, not data.
How much have Regeneron shareholders gained per year?
Earnings growth per share plus dividend.
An earnings-based proxy, not a stock-price total return - it doesn't capture multiple expansion/contraction or reinvested dividends. EPS from REGN's own 10-K filings; dividend yield is the current trailing yield on today's price, from the same weekly fetch as the rest of this site.
What do Regeneron's 10-year financials show?
From REGN's own 10-K filings (SEC EDGAR): up to the last 10 fiscal years. Press any year's bars for the exact figures.
Frequently asked questions about Regeneron
What kind of company is Regeneron?
Regeneron is a biotech company that discovers and sells antibody drugs. Its largest products treat eye disease (Eylea) and inflammatory conditions such as eczema and asthma (Dupixent, developed with Sanofi). Brands and businesses it owns include Eylea, Dupixent (with Sanofi), Libtayo and Praluent. This site groups it with Biotechnology stocks.
Is Regeneron trading above or below its DCF value?
At $819.09, REGN trades 35.9% above this site's neutral DCF value of $602.86 per share, a margin of safety of −35.9%. That DCF projects free cash flow for 10 years, with growth starting at 8% and fading to 2.5%, discounted at 10%; it is one set of assumptions, not a forecast. Test your own in the Intrinsic Value Calculator.
How many of this site's 8 value filters does Regeneron pass?
REGN passes 8 of 8. It passes Market Cap > $25B ($82.9B), Trailing P/E < 25 (19.16), PEG Ratio < 1.5 (1.04), Price/Book < 8 (2.62), Price/Sales < 7 (5.34), EPS Growth YoY > -5% (-4.5%), vs 50-day MA (±12%) (+3.5%) and vs 200-day MA (±12%) (+11.3%). The 8-filter list shows every stock that passes all of them.
What growth is Regeneron's share price pricing in?
At $819.09, REGN's free cash flow of $35.30 per share would have to grow 15.8% a year, fading to 2.5% by year 10, for this site's DCF (10% discount rate) to match the price. This site's baseline starts at 8%, so the price asks for more growth than the baseline. Change the assumptions.
Are Regeneron's reported earnings reliable?
This site's earnings-quality check rates REGN Strong · 1 watch. Beneish M-score −2.55 · accruals −1.2% of assets · 109% of profit arrived as cash · stock comp 6.9% of revenue · share count −2.3% a year. From the latest 10-K (year to Dec 2025). Concerns: stock-based compensation (on watch). The five checks are the Beneish M-score (manipulation risk), accruals, cash conversion, stock-based compensation and share dilution; the Earnings Quality Screener shows how each is graded.
When does Regeneron report earnings next?
Regeneron's next earnings report is expected on October 30, 2026, with analysts expecting earnings of $16.48 per share. Dates come from the Finnhub earnings calendar and can move. In its last 4 quarters it beat the estimate 4 times, by an average of +16.8%.
Where do these numbers come from?
- Financial statements: Regeneron's 10-K annual report for the year ended Dec 31, 2025, filed Feb 4, 2026 (filing index). Every earlier year in the 10-year financials comes from the company's older 10-K filings, all listed on SEC EDGAR.
- Prices and market data: quotes, P/E and analyst ratings from Finnhub; daily price history and the 52-week range from Twelve Data, both refreshed weekly. Short interest comes from FINRA, reported twice a month.
- How to check a figure: click any number in the card above to see its exact source, and read the Editorial Standards for every rule behind the checks.
About this Regeneron Pharmaceuticals Inc analysis
This page shows every value-investing check the site runs on Regeneron Pharmaceuticals Inc (REGN) in one place: the 8 mechanical filters, the Buffett and Lynch checklists, a margin of safety from a disclosed DCF, earnings quality, shareholder yield and how it ranks against its sector peers. The numbers come from SEC filings and public market data, refreshed weekly, and the same rules apply to every stock on the stock list. See Editorial Standards for the sources and the rules, or run your own filters in the stock screener.