COST vs MSFT: 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: MSFT 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. COST and MSFT 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 COST and MSFT 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.

Costco Wholesale operates a membership-based warehouse club chain. Members pay an annual fee (currently $65 for basic Gold Star, $130 for Executive) for access to Costco warehouses, where they can buy products at lower markups than traditional retailers. Costco operates approximately 900 warehouses globally, with the largest concentration in the United States plus meaningful presence in Canada, Mexico, the UK, Japan, South Korea, Taiwan, Australia, and other markets.

Full COST guide

Microsoft (MSFT) is one of the largest and most diversified technology companies in the world, operating across three reporting segments. Productivity and Business Processes includes Microsoft 365 (Office, Teams, Dynamics 365) and LinkedIn. Intelligent Cloud covers Azure, GitHub, server products, and enterprise services. More Personal Computing spans Windows, gaming (Xbox plus the acquired Activision Blizzard), Surface devices, and search via Bing. Azure is the second-largest cloud computing platform in the world behind AWS, and Microsoft 365 is the dominant productivity suite for businesses globally. AI is woven across all of it through the Copilot product line and a deep partnership with OpenAI, in which Microsoft is both the primary cloud provider and a major investor. The company was founded in 1975 by Bill Gates and Paul Allen, is headquartered in Redmond, Washington, and is led by CEO Satya Nadella (since 2014). Microsoft is consistently the largest or one of the two largest publicly traded US companies by market cap, with enormous recurring cash flow and a multi-decade dividend-growth streak.

Full MSFT guide

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

• COST drivers: Membership fee growth; International expansion.
• MSFT drivers: AI as the platform; Closing the gap with AWS in cloud.

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: Costco's premium valuation (about 48x trailing and 40x forward earnings in October 2026) embeds high expectations for continued same-store sales growth and margin expansion. For MSFT, the largest open question is the return on AI capex: Microsoft is spending more than $50 billion a year on AI and cloud infrastructure, and if enterprise adoption is slower than expected the payback stretches out.

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 COST if you believe its drivers more; MSFT 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 COST and MSFT guides.

COST. Costco trades at one of the highest P/E ratios in retail, about 48x trailing earnings in mid-October 2026, on the strength of the durable membership model, consistent same-store sales growth (comparable sales up 11.4% in September), and the long runway for international expansion. The multiple has eased from earlier peaks as earnings grew faster than the share price. Analysts rate it a buy with an average target near $1,066, and the valuation has compressed historically only during severe market drawdowns.

MSFT. Microsoft trades at ~30x trailing and ~22x forward earnings as of October 16, 2026, lower than the ~35x of early 2026 because fiscal 2026 EPS grew faster than the share price. The premium rests on growth, durability, margins, and AI exposure through Azure, and holds as long as Azure keeps growing double digits and the AI capex earns a return. All figures are approximate and refresh quarterly; the next report is October 28, 2026.

Headline figures (approximate, October 2026): COST shows revenue (fy2026) ~$303 billion, up ~10% YoY; Q4 up ~11% YoY, operating margin ~3.8% (low, by design; membership fees are the profit lever), net income (fy2026) ~$9.2 billion, eps (fy2026) ~$20.76; Q4 $6.75 vs ~$6.53 consensus; MSFT shows revenue (fy2026 ending june) ~$332 billion, up ~18% year over year, operating margin ~45%, among the highest of any company at Microsoft's scale, net income (fy2026) ~$134 billion, eps (ttm) ~$17.75.

COST and MSFT 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 COST and MSFT exposure against your real portfolio. It is not an investment adviser.