BSX vs MMSI: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of September 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.

Reading it: BSX is the cheaper of the two on forward earnings, but cheaper is not the same as better. Pair the valuation with growth (how far the forward P/E sits below the trailing P/E) and risk (beta) before you decide.

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. BSX and MMSI 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 BSX and MMSI 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.

Boston Scientific Corporation is a Marlborough, Massachusetts-based medical device company that develops, manufactures, and markets minimally invasive devices used in interventional cardiology, electrophysiology, structural heart, peripheral interventions, endoscopy, urology, neuromodulation, and cardiac rhythm management. It reports through two broad segments: Cardiovascular, which houses the fast-growing electrophysiology business (led by the Farapulse pulsed field ablation system) and the Watchman left-atrial-appendage closure franchise, and MedSurg, which spans endoscopy, urology, and neuromodulation. The company sells into hospitals and physicians across roughly 130 countries and competes at the leading edge of catheter-based and device-based procedures that substitute for more invasive surgery.

Full BSX guide

Merit Medical Systems designs, manufactures, and markets a broad catalog of single-use and capital medical devices used in minimally invasive procedures. Its business splits into two segments: Cardiovascular (peripheral intervention, cardiac intervention, interventional oncology and spine, and cardiovascular and critical care) and Endoscopy (non-vascular stents, balloon dilators, and related tools for gastroenterologists and pulmonologists). The company sells globally through direct sales forces and distributors, and it has grown revenue toward roughly $1.5 to $1.6 billion annually, driven by a mix of organic volume and frequent product-line acquisitions.

Full MMSI guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• BSX drivers: Farapulse and the Pulsed Field Ablation Wave; Watchman Franchise Expansion.
• MMSI drivers: Organic growth in interventional devices; Bolt-on acquisitions.

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: The most immediate concern flagged with 2026 guidance was unanticipated headwinds in electrophysiology, Watchman, and urology, which prompted management to frame organic growth guidance of 6.5% to 8%, below the pace of recent years and a signal that the newest franchises may be decelerating from peak growth rates. For MMSI, merit competes against far larger and better-capitalized device companies including Boston Scientific, Medtronic, Abbott, Teleflex, Becton Dickinson, and Terumo, which can pressure pricing and share.

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 BSX if you believe its drivers more; MMSI 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 BSX and MMSI guides.

BSX. Boston Scientific's trailing P/E of roughly 18x sits well below the peer-group average of roughly 34x cited by valuation trackers, a reversal from the sustained premium multiple the stock carried during its high-growth phase. The compression followed a steep share-price decline over the trailing year that coincided with a downward revision to organic growth guidance and disappointing signals in electrophysiology, Watchman, and urology. Net profit margin runs near 17%, and full-year 2026 adjusted EPS growth is guided to 9% to 11%, so the debate is whether the lower multiple reflects fair concern about decelerating growth or an over-correction relative to the franchise's still-double-digit earnings trajectory.

MMSI. Merit trades around a mid-20s to high-20s P/E on trailing GAAP earnings, a premium that reflects its consistency and acquisition-driven model. Q1 2026 revenue of about $382 million rose 7 percent year over year, with non-GAAP EPS of $0.94 beating expectations. Full-year 2026 guidance implies roughly 6 to 8 percent revenue growth and mid-to-high single-digit non-GAAP EPS growth.

Headline figures (approximate, July 2026): BSX shows revenue (ttm) ~$20.6 billion, revenue (fy 2025) ~$20 billion, q1 2026 revenue ~$5.2 billion (+11.6% YoY reported, ~9.4% organic), adjusted eps guidance (fy 2026) ~$3.34 to $3.41 (9% to 11% growth); MMSI shows revenue (ttm) ~$1.54B, market cap ~$4.0B, net income (ttm) ~$139M, p/e (gaap, ttm) ~27x.

BSX and MMSI 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 BSX and MMSI exposure against your real portfolio. It is not an investment adviser.