Should You Buy Costco Stock for the Long Haul? Here's the Honest Answer.

Costco is still growing, with first nine months of fiscal 2026 revenue up 10% to $207 billion and net income up 13% to about $6.2 billion, but the article argues that the stock's valuation is excessive. Shares trade at 49 times earnings, well above peers, and have been flat since early 2025 and pulling back since mid-May. The piece recommends investors keep Costco on a watch list rather than buy at current levels, suggesting better entry points only if the multiple falls below 35x.

Analysis

The setup is less about Costco’s operating quality and more about duration risk embedded in a defensive compounder. At ~50x earnings, the stock is effectively discounting several years of continued low-teens growth with minimal multiple compression; that makes it unusually sensitive to any slowdown in same-store sales, basket mix, or margin mix from gasoline and membership timing. In other words, the first-order story is “still good,” but the second-order issue is that good news is now a source of asymmetry against the stock because the market is already paying for near-flawless execution.

Competitive dynamics are mildly favorable for the rest of the large-cap retail cohort. If capital rotates out of COST, the most obvious relative beneficiaries are WMT and AMZN, which can absorb incremental “quality at a reasonable price” flows without needing to re-rate dramatically. TGT is a more tactical beneficiary only if investors reinterpret retail as a value/recovery trade; otherwise it remains a lower-quality substitute and likely gets less persistent inflow than WMT. The broader implication is that Costco’s premium can act as a sector barometer: if it stops working, that often signals a shift from “pay any price for resilience” toward “pay for earnings power with optionality.”

The contrarian point is that the market may be underestimating how long high-quality retailers can stay expensive in a slower-growth regime. A mild macro slowdown can actually support membership-led, necessity-driven models and keep earnings revisions positive even if the multiple compresses somewhat. That means the short case is not a fundamental collapse but a valuation reset; the most attractive entry may require either a broader market drawdown or an idiosyncratic miss that breaks the “always works” narrative over the next 1-2 quarters.

The key risk to the bearish view is that Costco’s valuation can remain elevated longer than expected if the company continues to print high-single-digit revenue growth and low-teens EPS growth while the market de-risks into cash-flow certainty. In that scenario, the stock may grind sideways rather than mean-revert sharply, which is painful for outright shorts and argues for defined-risk positioning rather than conviction shorting.

Key Decisions for Investors

• Avoid initiating an outright short in COST at current levels; use only defined-risk structures because the stock can stay expensive for months even if fundamentals remain merely good.
• Prefer a relative-value long WMT / short COST pair over the next 1-3 months: WMT should attract rotation if investors seek retail exposure with lower multiple risk, while COST remains vulnerable to multiple compression.
• If already long COST, trim into strength and replace part of the exposure with AMZN or WMT to preserve consumer defensiveness while reducing valuation risk.
• Consider a COST put spread 3-6 months out, struck around 10-15% below spot, to express a multiple-reset view with capped premium outlay and limited theta bleed.
• Set a buy alert only on a broader selloff or valuation washout; the risk/reward improves materially if COST de-rates into the mid-30s P/E range, where quality becomes cheap enough to own through a cycle.