VOL. XCIV, NO. 247

★ WIDE MOAT STOCKS COMPARISON ★

NO ADVICE

Tuesday, December 30, 2025

Stock Comparison

Gilead Sciences, Inc. vs Merck & Co., Inc.

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

Gilead Sciences, Inc.

GILD · NASDAQ Global Select Market

Market cap (USD)$155.6B
SectorHealthcare
CountryUS
Data as of2025-12-30
Moat score
74/ 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 Gilead Sciences, Inc.'s moat claims, evidence, and risks.

View GILD 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 gap: Gilead Sciences, Inc. leads (74 / 100 vs 71 / 100 for Merck & Co., Inc.).
  • Segment focus: Gilead Sciences, Inc. has 5 segments (68.5% in HIV); Merck & Co., Inc. has 2 segments (89.5% in Pharmaceutical).
  • Primary market structure: Oligopoly vs Competitive. Pricing power: Moderate vs Moderate.
  • Moat breadth: Gilead Sciences, Inc. has 8 moat types across 3 domains; Merck & Co., Inc. has 5 across 3.

Primary market context

Gilead Sciences, Inc.

HIV

Market

HIV treatment and prevention medicines (antiretroviral therapy and PrEP)

Geography

Global (U.S. and Europe are major markets)

Customer

Patients/prescribers; reimbursed by public and private payers; distributed via wholesalers and specialty pharmacies

Role

Drug developer and marketing authorization holder

Revenue share

68.5%

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

Gilead Sciences, Inc.
Merck & Co., Inc.
Ticker / Exchange
GILD - NASDAQ Global Select Market
MRK - New York Stock Exchange
Market cap (USD)
$155.6B
$250.9B
Sector
Healthcare
Healthcare
HQ country
US
US
Primary segment
HIV
Pharmaceutical
Market structure
Oligopoly
Competitive
Market share
50%-60% (reported)
n/a
HHI estimate
n/a
n/a
Pricing power
Moderate
Moderate
Moat score
74 / 100
71 / 100
Moat domains
Demand, Legal, Supply
Legal, Supply, Demand
Last update
2025-12-30
2025-12-22

Moat coverage

Shared moat types

IP Choke PointCapex Knowhow ScaleRegulated Standards Pipe

Gilead Sciences, Inc. strengths

Habit DefaultSwitching Costs GeneralService Field NetworkCompliance AdvantageBrand Trust

Merck & Co., Inc. strengths

Scope EconomiesData Workflow Lockin

Segment mix

Gilead Sciences, Inc. segments

Full profile >

HIV

Oligopoly

68.5%

Oncology (Cell Therapy + Trodelvy)

Oligopoly

11.5%

Liver Disease

Oligopoly

10.6%

Veklury (Remdesivir)

Competitive

6.3%

Other Products

Competitive

3.1%

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.