VOL. XCIV, NO. 247

★ WIDE MOAT STOCKS COMPARISON ★

NO ADVICE

Wednesday, December 31, 2025

Stock Comparison

Merck & Co., Inc. vs O'Reilly Automotive, Inc.

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

Merck & Co., Inc.

MRK · New York Stock Exchange

Market cap (USD)$250.9B
SectorHealthcare
CountryUS
Data as of2025-12-22
Moat score
71/ 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 Merck & Co., Inc.'s moat claims, evidence, and risks.

View MRK analysis

O'Reilly Automotive, Inc.

ORLY · Nasdaq Global Select Market

Market cap (USD)
SectorConsumer
CountryUS
Data as of2025-12-31
Moat score
63/ 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 O'Reilly Automotive, Inc.'s moat claims, evidence, and risks.

View ORLY analysis

Comparison highlights

  • Moat score gap: Merck & Co., Inc. leads (71 / 100 vs 63 / 100 for O'Reilly Automotive, Inc.).
  • Segment focus: Merck & Co., Inc. has 2 segments (89.5% in Pharmaceutical); O'Reilly Automotive, Inc. has 2 segments (52% in DIY Aftermarket Retail).
  • Primary market structure: Competitive vs Oligopoly. Pricing power: Moderate vs Moderate.
  • Moat breadth: Merck & Co., Inc. has 5 moat types across 3 domains; O'Reilly Automotive, Inc. has 7 across 2.

Primary market context

Merck & Co., Inc.

Pharmaceutical

Market

Branded prescription pharmaceuticals & human vaccines

Geography

Global

Customer

Wholesalers/retailers, managed care and government payers, hospitals/clinics

Role

R&D-intensive innovator, manufacturer, and marketer

Revenue share

89.5%

O'Reilly Automotive, Inc.

DIY Aftermarket Retail

Market

Specialty automotive aftermarket parts retail (DIY channel)

Geography

United States, Puerto Rico, Mexico, Canada

Customer

Consumers (do-it-yourself vehicle owners)

Role

Specialty retailer

Revenue share

52%

Side-by-side metrics

Merck & Co., Inc.
O'Reilly Automotive, Inc.
Ticker / Exchange
MRK - New York Stock Exchange
ORLY - Nasdaq Global Select Market
Market cap (USD)
$250.9B
n/a
Sector
Healthcare
Consumer
HQ country
US
US
Primary segment
Pharmaceutical
DIY Aftermarket Retail
Market structure
Competitive
Oligopoly
Market share
n/a
n/a
HHI estimate
n/a
n/a
Pricing power
Moderate
Moderate
Moat score
71 / 100
63 / 100
Moat domains
Legal, Supply, Demand
Supply, Demand
Last update
2025-12-22
2025-12-31

Moat coverage

Shared moat types

Scope Economies

Merck & Co., Inc. strengths

IP Choke PointRegulated Standards PipeCapex Knowhow ScaleData Workflow Lockin

O'Reilly Automotive, Inc. strengths

Supply Chain ControlPhysical Network DensityBrand TrustHabit DefaultService Field NetworkProcurement Inertia

Segment mix

Merck & Co., Inc. segments

Full profile >

Pharmaceutical

Competitive

89.5%

Animal Health

Oligopoly

9.2%

O'Reilly Automotive, Inc. segments

Full profile >

DIY Aftermarket Retail

Oligopoly

52%

Professional (B2B) Aftermarket Distribution

Competitive

48%

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.