Antitrust Radar
Competition InsightsAR-CI-2026-02 / Focused note

Defined markets / dispatch 02

Four digital usage systems traced four different structural paths.

Browser, mobile operating-system, search-engine, and social-referral shares are read side by side without turning them into one platform-power score.
Current readout4 systems
Exact signals
12
separate usage denominators
Entities
4
within declared frames
Public sources
4
linked custody rows
Latest anchor
2026
intervals vary
6 increased 6 decreased

Interpretation boundaryUsage and referral shares are proxies inside separately defined systems. The dispatch does not add shares across products, resolve legal market definition, or infer a common competitive cause.

Evidence standard

Evidence reading

What the current rows establish.

4 bounded findings / 12 exact signals
  1. 01

    Social-referral composition shifted toward the leader.

    Social referrals moved from 3,804 in 2025 to 4,995 in 2026 (+1,191.0 HHI points). Social referrals moved from 57.5% in 2025 to 68.9% in 2026 (+11.49 percentage points). Social referrals moved from 95.1% in 2025 to 94.4% in 2026 (-0.71 percentage points).

    3 supporting signals
  2. 02

    Search HHI and leading share both moved lower.

    Search engines moved from 7,589 in 2025 to 7,359 in 2026 (-230.0 HHI points). Search engines moved from 86.7% in 2025 to 85.2% in 2026 (-1.55 percentage points). Search engines moved from 99.4% in 2025 to 99.4% in 2026 (-0.02 percentage points).

    3 supporting signals
  3. 03

    Mobile operating-system HHI and leading share moved higher.

    Mobile operating systems moved from 5,094 in 2025 to 5,337 in 2026 (+243.0 HHI points). Mobile operating systems moved from 57.6% in 2025 to 63.1% in 2026 (+5.48 percentage points). Mobile operating systems moved from 100.0% in 2025 to 100.0% in 2026 (+0.04 percentage points).

    3 supporting signals
  4. 04

    Browser HHI and leading share moved lower while CR4 edged higher.

    Browsers moved from 3,720 in 2025 to 3,612 in 2026 (-108.0 HHI points). Browsers moved from 52.3% in 2025 to 50.0% in 2026 (-2.29 percentage points). Browsers moved from 93.6% in 2025 to 93.8% in 2026 (+0.15 percentage points).

    3 supporting signals

Exact comparisons

Inspect every prior and latest anchor.

Observed change fieldEach row retains its own unit and scale
  1. BrowsersCR4202593.610%202693.760%+0.150 ppIncrease
  2. BrowsersHHI20253,72020263,612-108 HHIDecrease
  3. BrowsersLeader share202552.320%202650.030%-2.290 ppDecrease
  4. Mobile operating systemsCR4202599.960%2026100.000%+0.040 ppIncrease
  5. Mobile operating systemsHHI20255,09420265,337+243 HHIIncrease
  6. Mobile operating systemsLeader share202557.600%202663.080%+5.480 ppIncrease
  7. Search enginesCR4202599.410%202699.390%-0.020 ppDecrease
  8. Search enginesHHI20257,58920267,359-230 HHIDecrease
  9. Search enginesLeader share202586.710%202685.160%-1.550 ppDecrease
  10. Social referralsCR4202595.090%202694.380%-0.710 ppDecrease
  11. Social referralsHHI20253,80420264,995+1,191 HHIIncrease
  12. Social referralsLeader share202557.450%202668.940%+11.490 ppIncrease

Analysis lab

Open the bounded instruments behind this dispatch.

5 declared routes / 12 signals
  1. 01

    VizBuilder figure

    Digital HHI release field

    Four separately defined usage systems on an exact HHI trend display.Each line retains its own product, denominator, participant set, and release record.
  2. 02

    VizBuilder figure

    Digital CR4 release field

    Four separately defined usage systems on an exact top-four-share trend display.Each line retains its own product, denominator, participant set, and release record.
  3. 03

    VizBuilder figure

    Digital leader-share field

    Four separately defined usage systems on an exact leading-participant-share display.Each line retains its own product, denominator, participant set, and release record.
  4. 04

    Exact relationship

    HHI and leader-share trajectory

    Exact same-release pairs for browser, mobile OS, search, and social referral.The association is partly mechanical and does not establish a common platform market or competitive cause.
  5. 05

    Source workspace

    Digital platform source systems

    All 12 dispatch signals inside the platform history and observation ledgers.The systems stay analytically separate even when viewed side by side.

Evidence ledger

Values, custody, and continuation routes.

Scroll horizontally to inspect all columns.
Digital gateways signal membership table. Values retain their source unit and period basis.
Entity / metricPriorLatestChangeSourceContinue
BrowsersFour-participant concentration ratio93.610%202593.760%2026+0.150 ppIncreaseStatCounter Global Statsstatcounter-browser-us-2026
VizBuilder Source system
BrowsersHerfindahl-Hirschman Index3,72020253,6122026-108 HHIDecreaseStatCounter Global Statsstatcounter-browser-us-2026
VizBuilder Source system
BrowsersLeading-participant share52.320%202550.030%2026-2.290 ppDecreaseStatCounter Global Statsstatcounter-browser-us-2026
VizBuilder Source system
Mobile operating systemsFour-participant concentration ratio99.960%2025100.000%2026+0.040 ppIncreaseStatCounter Global Statsstatcounter-mobile-os-us-2026
VizBuilder Source system
Mobile operating systemsHerfindahl-Hirschman Index5,09420255,3372026+243 HHIIncreaseStatCounter Global Statsstatcounter-mobile-os-us-2026
VizBuilder Source system
Mobile operating systemsLeading-participant share57.600%202563.080%2026+5.480 ppIncreaseStatCounter Global Statsstatcounter-mobile-os-us-2026
VizBuilder Source system
Search enginesFour-participant concentration ratio99.410%202599.390%2026-0.020 ppDecreaseStatCounter Global Statsstatcounter-search-us-2026
VizBuilder Source system
Search enginesHerfindahl-Hirschman Index7,58920257,3592026-230 HHIDecreaseStatCounter Global Statsstatcounter-search-us-2026
VizBuilder Source system
Search enginesLeading-participant share86.710%202585.160%2026-1.550 ppDecreaseStatCounter Global Statsstatcounter-search-us-2026
VizBuilder Source system
Social referralsFour-participant concentration ratio95.090%202594.380%2026-0.710 ppDecreaseStatCounter Global Statsstatcounter-social-referral-us-2026
VizBuilder Source system
Social referralsHerfindahl-Hirschman Index3,80420254,9952026+1,191 HHIIncreaseStatCounter Global Statsstatcounter-social-referral-us-2026
VizBuilder Source system
Social referralsLeading-participant share57.450%202568.940%2026+11.490 ppIncreaseStatCounter Global Statsstatcounter-social-referral-us-2026
VizBuilder Source system

Research handoff

The dispatch ends where investigation should begin.

Which defaults, distribution arrangements, switching paths, product changes, and participant-share movements account for each system's latest direction?
  1. BrowsersWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?
  2. BrowsersWhich entry, exit, share, switching, price, quality, or capacity evidence can explain the movement inside this exact market boundary?
  3. BrowsersWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?
  4. Mobile operating systemsWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?

Source custody

Public records behind this dispatch.

4 sources
  1. 01
    Mobile operating system market share in United States of America, April 2023-April 2026StatCounter Global Stats / accessed July 20, 2026
    Source dossier
  2. 02
    Social media referral share in United States of America, April 2023-April 2026StatCounter Global Stats / accessed July 20, 2026
    Source dossier
  3. 03
    Browser market share in United States of America, April 2023-April 2026StatCounter Global Stats / accessed July 17, 2026
    Source dossier
  4. 04
    Search engine market share in United States of America, April 2023-April 2026StatCounter Global Stats / accessed July 17, 2026
    Source dossier

Publication record

Cite this dispatch as a versioned research object.

current edition
Competition InsightsAR-CI-2026-02Version 1.0
Author
Antitrust Radar Research Team
Published
Updated
Sources checked
Antitrust Radar Research Team. (2026, August 12). Four digital usage systems traced four different structural paths.. Competition Insights, AR-CI-2026-02 (Version 1.0). Antitrust Radar. https://antitrustradar.org/insights/digital-gateways-change
BibTeXRIS