VOL. XCIV, NO. 247

★ WIDE MOAT STOCKS COMPARISON ★

NO ADVICE

Wednesday, December 31, 2025

Stock Comparison

GSK plc vs Marsh & McLennan Companies, Inc.

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

GSK plc

GSK · London Stock Exchange

Market cap (USD)$98.8B
SectorHealthcare
CountryGB
Data as of2025-12-28
Moat score
62/ 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 GSK plc's moat claims, evidence, and risks.

View GSK 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: Marsh & McLennan Companies, Inc. leads (65 / 100 vs 62 / 100 for GSK plc).
  • Segment focus: GSK plc has 3 segments (37.6% in Specialty Medicines); Marsh & McLennan Companies, Inc. has 2 segments (62.8% in Risk and Insurance Services).
  • Primary market structure: Oligopoly vs Oligopoly. Pricing power: Strong vs Moderate.
  • Moat breadth: GSK plc has 4 moat types across 3 domains; Marsh & McLennan Companies, Inc. has 5 across 3.

Primary market context

GSK plc

Specialty Medicines

Market

Branded specialty pharmaceuticals (HIV, oncology, immunology/respiratory)

Geography

Global

Customer

Hospitals, specialist physicians, payers

Role

Innovator & branded manufacturer

Revenue share

37.6%

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

GSK plc
Marsh & McLennan Companies, Inc.
Ticker / Exchange
GSK - London Stock Exchange
MMC - New York Stock Exchange
Market cap (USD)
$98.8B
n/a
Sector
Healthcare
Financials
HQ country
GB
US
Primary segment
Specialty Medicines
Risk and Insurance Services
Market structure
Oligopoly
Oligopoly
Market share
n/a
n/a
HHI estimate
n/a
n/a
Pricing power
Strong
Moderate
Moat score
62 / 100
65 / 100
Moat domains
Supply, Legal, Demand
Supply, Demand, Legal
Last update
2025-12-28
2025-12-31

Moat coverage

Shared moat types

Compliance AdvantageSwitching Costs General

GSK plc strengths

Capex Knowhow ScaleIP Choke Point

Marsh & McLennan Companies, Inc. strengths

Service Field NetworkBrand TrustData Workflow Lockin

Segment mix

GSK plc segments

Full profile >

Vaccines

Oligopoly

29.1%

Specialty Medicines

Oligopoly

37.6%

General Medicines

Competitive

33.2%

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.