VOL. XCIV, NO. 247
★ WIDE MOAT STOCKS COMPARISON ★
NO ADVICE
Wednesday, December 31, 2025
Stock Comparison
Costco Wholesale Corporation vs Marsh & McLennan Companies, Inc.
Compare moat strength, market structure, and segment coverage to understand how each company defends its edge.
Costco Wholesale Corporation
COST · Nasdaq Global Select Market
Weighted average of segment moat scores, combining moat strength, durability, confidence, market structure, pricing power, and market share.
Full stock profile
Dive deeper into Costco Wholesale Corporation's moat claims, evidence, and risks.
View COST analysisMarsh & McLennan Companies, Inc.
MMC · New York Stock Exchange
Weighted average of segment moat scores, combining moat strength, durability, confidence, market structure, pricing power, and market share.
Full stock profile
Dive deeper into Marsh & McLennan Companies, Inc.'s moat claims, evidence, and risks.
View MMC analysisComparison highlights
- Moat score gap: Costco Wholesale Corporation leads (80 / 100 vs 65 / 100 for Marsh & McLennan Companies, Inc.).
- Segment focus: Costco Wholesale Corporation has 2 segments (98.1% in Warehouse club retail); Marsh & McLennan Companies, Inc. has 2 segments (62.8% in Risk and Insurance Services).
- Primary market structure: Oligopoly vs Oligopoly. Pricing power: Weak vs Moderate.
- Moat breadth: Costco Wholesale Corporation has 6 moat types across 3 domains; Marsh & McLennan Companies, Inc. has 5 across 3.
Primary market context
Costco Wholesale Corporation
Warehouse club retail
Membership warehouse club retail (warehouse clubs, ancillary services, and e-commerce)
Global
Households and small businesses
Retailer (membership club)
98.1%
Marsh & McLennan Companies, Inc.
Risk and Insurance Services
Insurance brokerage, risk advisory, and reinsurance brokerage/services
Global
Enterprises, public entities, associations, and individuals (via broker/agent channels)
Intermediary + advisor (insurance/reinsurance market intermediary)
62.8%
Side-by-side metrics
Moat coverage
Shared moat types
Costco Wholesale Corporation strengths
Marsh & McLennan Companies, Inc. strengths
Segment mix
Costco Wholesale Corporation segments
Full profile >Warehouse club retail
Oligopoly
Membership fees (subscription)
Oligopoly
Marsh & McLennan Companies, Inc. segments
Full profile >Risk and Insurance Services
Oligopoly
Consulting
Competitive
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View the moat stocks listCuration & Accuracy
This directory blends AI‑assisted discovery with human curation. Entries are reviewed, edited, and organized with the goal of expanding coverage and sharpening quality over time. Your feedback helps steer improvements (because no single human can capture everything all at once).
Details change. Pricing, features, and availability may be incomplete or out of date. Treat listings as a starting point and verify on the provider’s site before making decisions. If you spot an error or a gap, send a quick note and I’ll adjust.