VOL. XCIV, NO. 247

★ WIDE MOAT STOCKS COMPARISON ★

NO ADVICE

Wednesday, December 31, 2025

Stock Comparison

American Tower Corporation vs Marsh & McLennan Companies, Inc.

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

American Tower Corporation

AMT · New York Stock Exchange

Market cap (USD)
SectorReal Estate
CountryUS
Data as of2025-12-31
Moat score
76/ 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 American Tower Corporation's moat claims, evidence, and risks.

View AMT analysis

Marsh & McLennan Companies, Inc.

MMC · New York Stock Exchange

Market cap (USD)
SectorFinancials
CountryUS
Data as of2025-12-31
Moat score
65/ 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 Marsh & McLennan Companies, Inc.'s moat claims, evidence, and risks.

View MMC analysis

Comparison highlights

  • Moat score gap: American Tower Corporation leads (76 / 100 vs 65 / 100 for Marsh & McLennan Companies, Inc.).
  • Segment focus: American Tower Corporation has 3 segments; Marsh & McLennan Companies, Inc. has 2 segments (62.8% in Risk and Insurance Services).
  • Moat breadth: American Tower Corporation has 6 moat types across 4 domains; Marsh & McLennan Companies, Inc. has 5 across 3.

Primary market context

American Tower Corporation

U.S. & Canada Communications Sites

Market

Wireless communications site leasing (macro towers, rooftops and DAS)

Geography

United States and Canada

Customer

Wireless carriers and other tenants (broadcast, data, government/municipal)

Role

Independent owner/operator of communications real estate (towerco)

Marsh & McLennan Companies, Inc.

Risk and Insurance Services

Market

Insurance brokerage, risk advisory, and reinsurance brokerage/services

Geography

Global

Customer

Enterprises, public entities, associations, and individuals (via broker/agent channels)

Role

Intermediary + advisor (insurance/reinsurance market intermediary)

Revenue share

62.8%

Side-by-side metrics

American Tower Corporation
Marsh & McLennan Companies, Inc.
Ticker / Exchange
AMT - New York Stock Exchange
MMC - New York Stock Exchange
Market cap (USD)
n/a
n/a
Sector
Real Estate
Financials
HQ country
US
US
Primary segment
U.S. & Canada Communications Sites
Risk and Insurance Services
Market structure
Oligopoly
Oligopoly
Market share
n/a
n/a
HHI estimate
n/a
n/a
Pricing power
Moderate
Moderate
Moat score
76 / 100
65 / 100
Moat domains
Demand, Legal, Supply, Network
Supply, Demand, Legal
Last update
2025-12-31
2025-12-31

Moat coverage

Shared moat types

Switching Costs General

American Tower Corporation strengths

Long Term ContractsPermits Rights Of WayPhysical Network DensityInteroperability HubCapacity Moat

Marsh & McLennan Companies, Inc. strengths

Service Field NetworkBrand TrustCompliance AdvantageData Workflow Lockin

Segment mix

American Tower Corporation segments

Full profile >

U.S. & Canada Communications Sites

Oligopoly

n/a

International Communications Sites

Oligopoly

n/a

Data Centers

Competitive

n/a

Marsh & McLennan Companies, Inc. segments

Full profile >

Risk and Insurance Services

Oligopoly

62.8%

Consulting

Competitive

37.2%

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.