VOL. XCIV, NO. 247

★ WIDE MOAT STOCKS COMPARISON ★

NO ADVICE

Wednesday, December 31, 2025

Stock Comparison

Automatic Data Processing, Inc. vs Merck & Co., Inc.

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

Automatic Data Processing, Inc.

ADP · NASDAQ

Market cap (USD)$105B
SectorTechnology
CountryUS
Data as of2025-12-30
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 Automatic Data Processing, Inc.'s moat claims, evidence, and risks.

View ADP analysis

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

Comparison highlights

  • Moat score: both at 71 / 100.
  • Segment focus: Automatic Data Processing, Inc. has 2 segments (67.5% in Employer Services); Merck & Co., Inc. has 2 segments (89.5% in Pharmaceutical).
  • Primary market structure: Oligopoly vs Competitive. Pricing power: Moderate vs Moderate.
  • Moat breadth: Automatic Data Processing, Inc. has 7 moat types across 4 domains; Merck & Co., Inc. has 5 across 3.

Primary market context

Automatic Data Processing, Inc.

Employer Services

Market

Payroll processing and cloud HCM (HR, time, talent, tax, benefits) software and outsourcing

Geography

Global

Customer

Businesses (SMB to large enterprise)

Role

SaaS and managed services provider

Revenue share

67.5%

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%

Side-by-side metrics

Automatic Data Processing, Inc.
Merck & Co., Inc.
Ticker / Exchange
ADP - NASDAQ
MRK - New York Stock Exchange
Market cap (USD)
$105B
$250.9B
Sector
Technology
Healthcare
HQ country
US
US
Primary segment
Employer Services
Pharmaceutical
Market structure
Oligopoly
Competitive
Market share
16.7% (reported)
n/a
HHI estimate
n/a
n/a
Pricing power
Moderate
Moderate
Moat score
71 / 100
71 / 100
Moat domains
Demand, Legal, Supply, Financial
Legal, Supply, Demand
Last update
2025-12-30
2025-12-22

Moat coverage

Shared moat types

Regulated Standards Pipe

Automatic Data Processing, Inc. strengths

Switching Costs GeneralCompliance AdvantageScale Economies Unit CostFloat PrepaymentSuite BundlingUnderwriting Risk Pooling

Merck & Co., Inc. strengths

IP Choke PointCapex Knowhow ScaleScope EconomiesData Workflow Lockin

Segment mix

Automatic Data Processing, Inc. segments

Full profile >

Employer Services

Oligopoly

67.5%

Professional Employer Organization (PEO) Services

Competitive

32.5%

Merck & Co., Inc. segments

Full profile >

Pharmaceutical

Competitive

89.5%

Animal Health

Oligopoly

9.2%

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.