VOL. XCIV, NO. 247

★ WIDE MOAT STOCKS COMPARISON ★

NO ADVICE

Saturday, January 10, 2026

Stock Comparison

Arthur J. Gallagher & Co. vs Costco Wholesale Corporation

Compare moat strength, market structure, and segment coverage to understand how each company defends its edge.

Arthur J. Gallagher & Co.

AJG · New York Stock Exchange

Market cap (USD)$67.9B
Gross margin (TTM)
Operating margin (TTM)
Net margin (TTM)
SectorFinancials
IndustryInsurance - Brokers
CountryUS
Data as of2026-01-09
Moat score
69/ 100

Weighted average of segment moat scores, combining moat strength, durability, confidence, market structure, pricing power, and market share.

Full stock profile

Dive deeper into Arthur J. Gallagher & Co.'s moat claims, evidence, and risks.

View AJG analysis

Costco Wholesale Corporation

COST · Nasdaq Global Select Market

Market cap (USD)$410.5B
Gross margin (TTM)12.9%
Operating margin (TTM)3.8%
Net margin (TTM)3%
SectorConsumer
IndustryDiscount Stores
CountryUS
Data as of2025-12-21
Moat score
80/ 100

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 analysis

Comparison highlights

  • Moat score gap: Costco Wholesale Corporation leads (80 / 100 vs 69 / 100 for Arthur J. Gallagher & Co.).
  • Segment focus: Arthur J. Gallagher & Co. has 2 segments (86% in Brokerage); Costco Wholesale Corporation has 2 segments (98.1% in Warehouse club retail).
  • Primary market structure: Oligopoly vs Oligopoly. Pricing power: Moderate vs Weak.
  • Moat breadth: Arthur J. Gallagher & Co. has 4 moat types across 2 domains; Costco Wholesale Corporation has 6 across 3.

Primary market context

Arthur J. Gallagher & Co.

Brokerage

Market

Insurance and reinsurance brokerage and consulting

Geography

Global

Customer

Commercial, industrial, public sector, nonprofit and other organizations; underwriting enterprises for reinsurance placements

Role

Intermediary / broker / advisor

Revenue share

86%

Costco Wholesale Corporation

Warehouse club retail

Market

Membership warehouse club retail (warehouse clubs, ancillary services, and e-commerce)

Geography

Global

Customer

Households and small businesses

Role

Retailer (membership club)

Revenue share

98.1%

Side-by-side metrics

Arthur J. Gallagher & Co.
Costco Wholesale Corporation
Ticker / Exchange
AJG - New York Stock Exchange
COST - Nasdaq Global Select Market
Market cap (USD)
$67.9B
$410.5B
Gross margin (TTM)
n/a
12.9%
Operating margin (TTM)
n/a
3.8%
Net margin (TTM)
n/a
3%
Sector
Financials
Consumer
Industry
Insurance - Brokers
Discount Stores
HQ country
US
US
Primary segment
Brokerage
Warehouse club retail
Market structure
Oligopoly
Oligopoly
Market share
n/a
n/a
HHI estimate
n/a
n/a
Pricing power
Moderate
Weak
Moat score
69 / 100
80 / 100
Moat domains
Supply, Demand
Supply, Financial, Demand
Last update
2026-01-09
2025-12-21

Moat coverage

Shared moat types

Brand TrustOperational Excellence

Arthur J. Gallagher & Co. strengths

Service Field NetworkData Workflow Lockin

Costco Wholesale Corporation strengths

Scale Economies Unit CostNegative Working CapitalHabit DefaultFloat Prepayment

Segment mix

Arthur J. Gallagher & Co. segments

Full profile >

Brokerage

Oligopoly

86%

Risk Management

Competitive

14%

Costco Wholesale Corporation segments

Full profile >

Warehouse club retail

Oligopoly

98.1%

Membership fees (subscription)

Oligopoly

1.9%

Want the full wide moat stocks list?

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Curation & 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.