VOL. XCIV, NO. 247

* WIDE MOAT STOCKS COMPARISON *

NO ADVICE

Sunday, December 28, 2025

Stock Comparison

GSK plc vs Merck & Co., 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.

View full moat 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.

View full moat analysis >

Side-by-side metrics

GSK plc
Merck & Co., Inc.
Ticker / Exchange
GSK - London Stock Exchange
MRK - New York Stock Exchange
Market cap (USD)
$98.8B
$250.9B
Sector
Healthcare
Healthcare
HQ country
GB
US
Primary segment
Specialty Medicines
Pharmaceutical
Market structure
Oligopoly
Competitive
Market share
n/a
n/a
HHI estimate
n/a
n/a
Pricing power
Strong
Moderate
Moat score
62 / 100
71 / 100
Moat domains
Supply, Legal, Demand
Legal, Supply, Demand
Last update
2025-12-28
2025-12-22

Moat coverage

Shared moat types

Capex Knowhow ScaleIP Choke Point

GSK plc strengths

Compliance AdvantageSwitching Costs General

Merck & Co., Inc. strengths

Regulated Standards PipeScope EconomiesData Workflow Lockin

Segment mix

GSK plc segments

Full profile >

Vaccines

Oligopoly

29.1%

Specialty Medicines

Oligopoly

37.6%

General Medicines

Competitive

33.2%

Merck & Co., Inc. segments

Full profile >

Pharmaceutical

Competitive

89.5%

Animal Health

Oligopoly

9.2%

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 Pricing, features, and availability may be incomplete or out of date.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.