VOL. XCIV, NO. 247

★ WIDE MOAT STOCKS COMPARISON ★

NO ADVICE

Wednesday, December 31, 2025

Stock Comparison

Aon plc vs West Pharmaceutical Services, Inc.

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

Aon plc

AON · New York Stock Exchange

Market cap (USD)$76.6B
SectorFinancials
CountryIE
Data as of2025-12-31
Moat score
70/ 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 Aon plc's moat claims, evidence, and risks.

View AON analysis

West Pharmaceutical Services, Inc.

WST · New York Stock Exchange

Market cap (USD)
SectorHealthcare
CountryUS
Data as of2025-12-22
Moat score
85/ 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 West Pharmaceutical Services, Inc.'s moat claims, evidence, and risks.

View WST analysis

Comparison highlights

  • Moat score gap: West Pharmaceutical Services, Inc. leads (85 / 100 vs 70 / 100 for Aon plc).
  • Segment focus: Aon plc has 2 segments (67% in Risk Capital); West Pharmaceutical Services, Inc. has 2 segments (80.7% in Proprietary Products).
  • Primary market structure: Oligopoly vs Quasi-Monopoly. Pricing power: Moderate vs Moderate.
  • Moat breadth: Aon plc has 6 moat types across 3 domains; West Pharmaceutical Services, Inc. has 5 across 3.

Primary market context

Aon plc

Risk Capital

Market

Large-account commercial insurance & reinsurance brokerage and risk advisory

Geography

Global

Customer

Enterprises, insurers, reinsurers

Role

Intermediary/advisor

Revenue share

67%

West Pharmaceutical Services, Inc.

Proprietary Products

Market

Injectable primary packaging components and containment/delivery systems (elastomeric stoppers, seals, plungers, syringe/cartridge components; related services)

Geography

Global

Customer

Biologic, generic, and pharmaceutical drug manufacturers

Role

Primary packaging and delivery component supplier

Revenue share

80.7%

Side-by-side metrics

Aon plc
West Pharmaceutical Services, Inc.
Ticker / Exchange
AON - New York Stock Exchange
WST - New York Stock Exchange
Market cap (USD)
$76.6B
n/a
Sector
Financials
Healthcare
HQ country
IE
US
Primary segment
Risk Capital
Proprietary Products
Market structure
Oligopoly
Quasi-Monopoly
Market share
n/a
70%-75% (reported)
HHI estimate
n/a
n/a
Pricing power
Moderate
Moderate
Moat score
70 / 100
85 / 100
Moat domains
Demand, Supply, Legal
Demand, Legal, Supply
Last update
2025-12-31
2025-12-22

Moat coverage

Shared moat types

Brand TrustCompliance Advantage

Aon plc strengths

Data Workflow LockinSwitching Costs GeneralService Field NetworkScale Economies Unit Cost

West Pharmaceutical Services, Inc. strengths

Design In QualificationCapex Knowhow ScaleOperational Excellence

Segment mix

Aon plc segments

Full profile >

Risk Capital

Oligopoly

67%

Human Capital

Oligopoly

33.2%

West Pharmaceutical Services, Inc. segments

Full profile >

Proprietary Products

Quasi-Monopoly

80.7%

Contract-Manufactured Products

Competitive

19.3%

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.