Antitrust Radar
Merger activity observatory

Scenario analysis / observed shares

Merger structure lab

Calculate a hypothetical concentration change from two published participant shares. This is an arithmetic screen, not a claim that a transaction exists or a legal conclusion.

Live scenarioBing+Yahoo Search
Delta HHI+52.44Post HHI7,411.44
Eligible markets
6
Observed firm-level shares
Observed periods
18
Definition-matched snapshots
Complete HHI screens
17
Baseline and post-merger HHI
Share observations
136
Named, source-labeled rows
Scenario layer

Market, observed period, and two source-labeled participants can change.

Evidence layer

Published shares, baseline HHI, source status, confidence, and definition remain fixed.

Interpretation layer

Numeric conditions are screening inputs, never a standalone liability or outcome claim.

Observed-share scenario

Structure screen

Search enginesUnited StatesPublic proxyUsage shares99.88%named share coverageComplete HHIMedium confidence

Digital platforms / 2026

Bing + Yahoo Search

2 x 9.82% x 2.67% = 52.44 HHI points
Numeric condition not crossedThe selected shares do not cross either published Guideline 1 numeric path on these inputs.
Baseline HHI
7,359
2026 published anchor
Delta HHI
+52.44
Exact 2ab arithmetic
Post-merger HHI
7,411.44
Published baseline + delta
Merged share
12.49%
9.82% + 2.67%
Participant geometryObserved shares, combined only for this scenario
Observed2026
CombinedScenario
Google Search85.16%Bing + Yahoo Search12.49%DuckDuckGo1.74%Yandex0.38%Other search engines0.12%Ecosia0.11%
Guideline 1 numeric pathsOfficial reference
Guideline 1 HHI threshold planePost-merger HHI is plotted horizontally and the merger-related HHI increase vertically. The published numeric path is above 1,800 post-merger HHI and above 100 delta HHI. The selected scenario plots at post-merger HHI 7411.44 and delta HHI 52.44.02,5005,0007,50010,0000250500HHI 1,800Delta 100Post-merger HHIDelta HHI
Merged-firm share path12.49%

Share above 30% and delta HHI above 100: not crossed

Evidence contractOpen market profile

The scenario inherits this published boundary

Product
All-platform search engine usage
Geography
United States
Measurement
StatCounter search engine referral usage share
Denominator
Observed U.S. search engine usage in each reported monthly snapshot

IncludedNamed search engines and a residual Other category that closes the public share table to 100 percent

ExcludedSearch query volume, search advertising revenue, and other digital advertising activity

LimitationUsage share is a web-analytics proxy and should not be presented as search-query share or search-advertising revenue share.

Reusable scenario packet

Carry the exact inputs into research

Antitrust Radar, Merger Structure Lab: Bing + Yahoo Search in U.S. search engine usage (2026); observed shares 9.82% and 2.67%; ΔHHI 52.44; post-merger HHI 7411.44.
JSONCSV

Source custody

Search engine market share in United States of America, April 2023-April 2026StatCounter Global Stats2023 Merger Guidelines, Guideline 1U.S. Department of Justice and Federal Trade Commission / December 18, 2023

01This tool combines two observed shares as a research scenario. It does not report an actual transaction, define a legal market, or predict an agency or court outcome.

02The calculation inherits the published public proxy boundary, United States, measurement basis, denominator, and source limitations shown below.

03The post-merger HHI adds the exact share-based delta to the published, rounded baseline HHI; small rounding differences can remain.

04Guideline 1 concentration arithmetic is one screening framework. The Merger Guidelines identify additional fact-specific theories, evidence, and rebuttal considerations.

The JSON and CSV packets preserve the selected shares, arithmetic, thresholds, evidence status, definition contract, sources, citation, and guardrails.

Merger Structure Lab | Antitrust Radar