MRNA vs REGN: Which Is the Better Buy in 2026?
Last updated August 2026
Short answer
REGN is the larger of the two ($78.52B market cap): the incumbent the market prices for continued execution (12.78x forward earnings, beta 0.24). MRNA is the smaller challenger ($21.75B), priced similarly on forward earnings (-11.37x): more room to run, but more to prove. The real question is which set of drivers you believe, and whether owning one (or both) leaves you over-concentrated.
MRNA vs REGN: the tie-breaker metrics
Same yardstick, side by side (as of August 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.
| Metric | MRNA | REGN | What it tells you |
|---|---|---|---|
| Market cap | $21.75B | $78.52B | Size. The larger name is the incumbent; the smaller has more room to grow and more to prove. |
| Forward P/E | -11.37 | 12.78 | Valuation on next year's expected earnings, the same yardstick for both. Lower is cheaper for that growth; higher means the market is paying up. |
| Beta | 0.94 | 0.24 | Volatility vs the market. Above 1 swings harder than the index; below 1 is steadier. Higher beta means bigger drawdowns to hold through. |
| Price vs 52-week range | 51% of range | 79% of range | Where today's price sits between the 52-week low and high. Near the high is momentum with less margin of safety; near the low is out of favor or a discount, depending on why. |
| Price / book | 2.94 | 2.47 | How much you pay over book value. Very high can signal an asset-light, high-return business or a rich price. |
Before you buy: how MRNA and REGN affect your concentration
The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. MRNA and REGN share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.
This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined MRNA and REGN exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.
What does Moderna (MRNA) do?
Moderna is a Cambridge, Massachusetts biotechnology company built entirely around messenger RNA (mRNA) technology, the platform behind its Spikevax COVID-19 vaccine. After generating enormous pandemic-era revenue, demand has fallen sharply, and the company is trying to broaden beyond COVID into a wider vaccine and therapeutics franchise. Its approved and near-market products include Spikevax, the mRESVIA RSV vaccine for older adults, and newer respiratory approvals in Europe (mNEXSPIKE and the mCOMBRIAX combination shot), while its most watched late-stage assets are the mRNA-1010 seasonal flu vaccine and intismeran autogene (mRNA-4157), a personalized cancer vaccine developed with Merck.
What does Regeneron Pharmaceuticals (REGN) do?
Regeneron makes money primarily through two large franchises. Dupixent, an anti-inflammatory antibody used for eczema, asthma, COPD, and other conditions, is developed and commercialized in collaboration with Sanofi, and Regeneron records its share through Sanofi collaboration revenue (about $1.6 billion in Q1 2026, up roughly 36%). Eylea and the higher-dose Eylea HD treat retinal diseases such as wet age-related macular degeneration and diabetic eye disease, generating combined U.S. net product sales of about $941 million in Q1 2026, with Eylea HD now roughly half of that mix. Libtayo in oncology and a pipeline of nearly 50 clinical candidates round out the revenue base.
MRNA vs REGN: how do they differ?
Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.
- MRNA drivers: Respiratory franchise beyond COVID; Oncology optionality via Merck partnership.
- REGN drivers: Dupixent keeps compounding; A deep, diversified pipeline.
Which fits which kind of investor
A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: Revenue has fallen dramatically from pandemic highs and COVID demand remains uncertain, so the current business does not cover operating costs. For REGN, the clearest risk is Eylea biosimilar erosion.
MRNA or REGN: which should you pick?
Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick MRNA if you believe its drivers more; REGN if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the MRNA and REGN guides.
MRNA vs REGN: the full fundamentals
MRNA. MRNA trades on pipeline potential rather than current earnings, since it is loss-making with revenue far below its pandemic peak. Traditional multiples like P/E are not meaningful while the company is unprofitable, so the market is effectively pricing the odds of flu, combination, and cancer-vaccine programs succeeding. The multibillion-dollar cash balance is a key reason the company can fund that pipeline toward its 2028 break-even goal.
REGN. Figures are approximate and tied to the asOf date; verify current numbers with a live quote before acting. Regeneron reported about 19% revenue growth and adjusted EPS of roughly $9.47 in Q1 2026, beating estimates, and authorized an additional $3 billion buyback. The mid-teens P/E reflects the market weighing strong Dupixent growth against expected Eylea biosimilar erosion.
Headline figures (approximate, July 2026): MRNA shows market cap ~$20 billion, q1 2026 revenue ~$400 million, q1 2026 net loss ~$1.3 billion (incl. ~$878M legal charge), 2026 revenue growth guidance up to ~10%; REGN shows total revenue (ttm, approx) ~$14 billion, q1 2026 total revenue ~$3.6 billion (up ~19% YoY), dupixent global net sales (q1 2026) ~$4.9 billion (up ~31%), eylea + eylea hd u.s. net sales (q1 2026) ~$941 million combined.
The bottom line: MRNA vs REGN
MRNA and REGN are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined MRNA and REGN exposure against your real portfolio. It is not an investment adviser.
Wondering how MRNA or REGN fits the portfolio you already own? Walnut is an AI investing app that connects your brokerage read-only and answers questions like that about your actual holdings: overlap, concentration, and how each position tracks the S&P 500. Compare the best AI portfolio analyzers or see the best AI investing apps in 2026.
Investing in Moderna with AI
Connect the broker you already use and ask Walnut's AI how MRNA fits what you actually hold: whether you own it already through a fund, what it would do to your concentration, and how it has tracked the S&P 500. Read-only by default, and you approve anything before it reaches your broker.
FAQ
What is the difference between MRNA and REGN?
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Moderna is a Cambridge, Massachusetts biotechnology company built entirely around messenger RNA (mRNA) technology, the platform behind its Spikevax COVID-19 vaccine. Regeneron makes money primarily through two large franchises. They show up together because they share investment themes, but they are different businesses, so the better fit depends on which thesis you are expressing.
Is MRNA or REGN the better stock?
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Neither is universally better. REGN is the larger incumbent; MRNA is the smaller challenger and looks cheaper on forward earnings. Walnut is informational, not investment advice. Compare what each does, the tie-breaker metrics above, and the risks, then decide which fits your thesis and what you already own.
Which is cheaper, MRNA or REGN?
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On forward P/E (as of August 2026), MRNA trades at -11.37x and REGN at 12.78x, so MRNA is the cheaper of the two on next year's expected earnings. A lower multiple is not automatically the better buy: a richer valuation can be justified by faster growth, and a lower one can reflect real risk. Weigh the multiple against how fast each business is compounding.
Should you own both MRNA and REGN?
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Because they share themes, owning both concentrates you in that theme. That can be intentional (a focused bet) or accidental (less diversification than it looks). Walnut can show your combined exposure across both, and whether adding either over-concentrates you, before you buy.
What are the risks of MRNA vs REGN?
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MRNA: Revenue has fallen dramatically from pandemic highs and COVID demand remains uncertain, so the current business does not cover operating costs. The company is loss-making and burning cash, making it dependent on pipeline approvals landing on schedule. Regulatory risk is concrete: the FDA issued a Refusal-to-File letter for the flu vaccine earlier in 2026, and shifting U.S. vaccine policy adds uncertainty. Large legal settlements (such as the Arbutus and Genevant charge) can swing reported results, and much of the long-term value depends on the Merck-partnered cancer vaccine succeeding in Phase 3, which is far from guaranteed. REGN: The clearest risk is Eylea biosimilar erosion. Amgen's Pavblu launched in late 2024 and pressured sales, and settlements clear paths for Sandoz, and Alvotech and Teva, to launch competing copies in the U.S. around the fourth quarter of 2026, with erosion expected to accelerate. Eylea HD and Dupixent growth are the offsets, but the timing gap matters. The business is also concentrated in a few franchises, so a single setback in Dupixent or a major pipeline failure would weigh heavily, and the collaboration structure with Sanofi means Regeneron does not control all of its largest product's economics.
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Walnut is informational, not investment advice. This page is descriptive and not a recommendation to buy or sell MRNA or REGN; figures are approximate and dated (as of August 2026). Verify current data before investing.