VOL. XCIV, NO. 247

★ WIDE MOAT STOCKS COMPARISON ★

NO ADVICE

Friday, January 2, 2026

Stock Comparison

CoStar Group, Inc. vs Martin Marietta Materials, Inc.

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

CoStar Group, Inc.

CSGP · NASDAQ

Market cap (USD)$27.9B
Gross margin (TTM)79.3%
Operating margin (TTM)-2.7%
Net margin (TTM)0.7%
SectorReal Estate
IndustryReal Estate - Services
CountryUS
Data as of2025-12-29
Moat score
75/ 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 CoStar Group, Inc.'s moat claims, evidence, and risks.

View CSGP analysis

Martin Marietta Materials, Inc.

MLM · NYSE

Market cap (USD)$37.9B
Gross margin (TTM)
Operating margin (TTM)
Net margin (TTM)
SectorMaterials
IndustryConstruction Materials
CountryUS
Data as of2026-01-01
Moat score
78/ 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 Martin Marietta Materials, Inc.'s moat claims, evidence, and risks.

View MLM analysis

Comparison highlights

  • Moat score gap: Martin Marietta Materials, Inc. leads (78 / 100 vs 75 / 100 for CoStar Group, Inc.).
  • Segment focus: CoStar Group, Inc. has 6 segments (39% in Multifamily (Apartments.com Network)); Martin Marietta Materials, Inc. has 3 segments (52.4% in East Group).
  • Moat breadth: CoStar Group, Inc. has 9 moat types across 4 domains; Martin Marietta Materials, Inc. has 4 across 2.

Primary market context

CoStar Group, Inc.

Multifamily (Apartments.com Network)

Market

Online multifamily rental marketplaces and advertising

Geography

United States

Customer

Two-sided (renters + property managers/owners)

Role

Marketplace (subscription advertising + workflow tools)

Revenue share

39%

Martin Marietta Materials, Inc.

East Group

Market

Construction aggregates and asphalt products (crushed stone, sand & gravel; asphalt) in local/regional markets

Geography

United States (East/Southeast and adjacent regions)

Customer

Infrastructure agencies, construction contractors, and downstream materials producers (asphalt/ready-mix)

Role

Quarry/mining operator and building materials producer/distributor

Revenue share

52.4%

Side-by-side metrics

CoStar Group, Inc.
Martin Marietta Materials, Inc.
Ticker / Exchange
CSGP - NASDAQ
MLM - NYSE
Market cap (USD)
$27.9B
$37.9B
Gross margin (TTM)
79.3%
n/a
Operating margin (TTM)
-2.7%
n/a
Net margin (TTM)
0.7%
n/a
Sector
Real Estate
Materials
Industry
Real Estate - Services
Construction Materials
HQ country
US
US
Primary segment
Multifamily (Apartments.com Network)
East Group
Market structure
Oligopoly
Oligopoly
Market share
n/a
n/a
HHI estimate
n/a
n/a
Pricing power
Strong
Strong
Moat score
75 / 100
78 / 100
Moat domains
Supply, Network, Demand, Legal
Supply, Financial
Last update
2025-12-29
2026-01-01

Moat coverage

Shared moat types

Capex Knowhow Scale

CoStar Group, Inc. strengths

Data Network EffectsData Workflow LockinDe Facto StandardIP Choke PointTwo Sided NetworkBrand TrustSuite BundlingEcosystem Complements

Martin Marietta Materials, Inc. strengths

Physical Network DensityGeographic NaturalBenchmark Pricing Power

Segment mix

CoStar Group, Inc. segments

Full profile >

CoStar (commercial real estate info & analytics)

Oligopoly

37.3%

Information Services (lease management software + international info)

Competitive

5%

Multifamily (Apartments.com Network)

Oligopoly

39%

LoopNet (commercial property marketing marketplace)

Oligopoly

10.3%

Residential (Homes.com + OnTheMarket)

Oligopoly

3.7%

Other Marketplaces (Ten-X, Land.com, BizBuySell, etc.)

Competitive

4.8%

Martin Marietta Materials, Inc. segments

Full profile >

East Group

Oligopoly

52.4%

West Group

Oligopoly

40.9%

Specialties (formerly Magnesia Specialties)

Oligopoly

6.7%

Want the full wide moat stocks list?

Browse the full ranking of wide moat stocks, updated with moat scores and segment context.

View the moat stocks list

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.