AVTR vs TMO: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of October 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: AVTR 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. AVTR and TMO 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 AVTR and TMO 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.

Avantor, Inc. is a global provider of high-purity materials, consumables, equipment, and specialized services used across biopharma, healthcare, education, government, and advanced technology markets. Founded in 1904 and headquartered in Radnor, Pennsylvania, the company sells everything from high-purity chemicals and reagents, lab supplies, and customized excipients to single-use assemblies, chromatography resins, and fluid handling systems. It reorganized around two reporting segments (Laboratory Solutions and a Bioscience and Medtech Products grouping), and a large share of its revenue is recurring consumables that customers reorder repeatedly, which gives the model a razor-and-blade quality tied to laboratory activity and biologic manufacturing volumes.

Full AVTR guide

Thermo Fisher Scientific, headquartered in Waltham, Massachusetts, is a global provider of scientific instruments, consumables, reagents, and services used across pharmaceutical and biotech drug development, clinical diagnostics, academic research, and environmental and industrial testing. The company operates through four reportable segments: Life Sciences Solutions (reagents, proteins, and consumables for research and bioproduction), Analytical Instruments (mass spectrometers, chromatography systems, electron microscopes, and laboratory equipment), Specialty Diagnostics (clinical diagnostic kits and transplant diagnostics), and Laboratory Products and Biopharma Services (supply-chain distribution, contract research through PPD, and contract drug manufacturing through Patheon). Revenue is generated through instrument sales, high-margin consumables and reagents that customers repurchase continuously, long-term service contracts, and growing contract development and manufacturing (CDMO) fees; consumables and services collectively account for a majority of annual sales and provide durable recurring revenue.

Full TMO guide

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

• AVTR drivers: Revival transformation program; Recurring consumables and bioprocessing exposure.
• TMO drivers: Bioprocessing and Biologic Drug Manufacturing Tailwind; Recurring Consumables and Reagents Engine.

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: Avantor's revenue was only flat in Q2 2026 and consensus still implies a roughly 5.5% year-over-year decline for Q3, so the growth recovery remains unproven and could stall if biopharma and academic customers keep spending cautiously. For TMO, the most significant near-term risk is a contraction in research funding from government agencies (including NIH) and from biotech companies whose access to capital markets has historically been cyclical; when funding tightens, customers delay instrument purchases and reduce consumable orders, pressuring organic revenue growth.

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 AVTR if you believe its drivers more; TMO 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 AVTR and TMO guides.

AVTR. As of October 2026 Avantor trades at about 18.5x forward earnings and about 1.7x sales, a valuation that has re-rated sharply since the summer as two straight beats eased fears about the turnaround. It still sits at a discount to larger, higher-margin tools peers because of its slower growth and higher leverage. Figures are approximate and reference reported results through Q2 2026 and consensus estimates as of October 16, 2026.

TMO. Thermo Fisher's multiple has expanded sharply since mid-2026 as organic growth re-accelerated: the stock trades at roughly 25 times forward earnings and ~37 times trailing GAAP earnings, which include heavy acquisition amortization. Analysts expect 2026 adjusted EPS of ~$25.14 on ~$47.9 billion of revenue, and ~$27.58 on ~$50.4 billion in 2027, both roughly 10% growth. The October 21 third-quarter report will test whether the second quarter's 5% organic growth holds; free cash flow of roughly $6.3 billion in 2025 still gives the company flexibility for repurchases, dividends and acquisitions.

Headline figures (approximate, October 2026): AVTR shows revenue (ttm) ~$6.56B, q2 2026 revenue ~$1.69B (flat YoY, ~5% above estimates), gross / operating margin ~32% / ~7%, net income (ttm, gaap) ~-$578M (Q3 2025 write-down); TMO shows revenue (ttm) ~$46.3 billion; full year 2025 ~$44.6 billion, q2 2026 revenue ~$11.99 billion, up 10% reported and 5% organic, q2 2026 adjusted eps ~$6.03 (+13%) vs ~$5.71 expected, margins (ttm) Gross ~41%, GAAP operating ~19%, net ~15%.

AVTR and TMO 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 AVTR and TMO exposure against your real portfolio. It is not an investment adviser.