Competition Research BriefsAR-RB-2026-03

State Banking Structure, 2015-2025

Stable national concentration can coexist with large state-level shifts

By Antitrust Radar Research TeamResearch briefJul 20, 2026Version 1.0 · Current edition

Central finding

Statewide deposit concentration rose in 26 jurisdictions and fell in 25 between 2015 and 2025. The national index changed from 410 to 401.

Statewide branch-deposit screens are not legal banking markets. Changes can reflect ownership reporting or branch booking as well as consolidation; they do not establish a cause or competitive harm.

1
source: 51
state screens: 7
class shifts

Publication accountability

External review: No external review registered for version 1.0
Recorded source access / review: 2026-07-19. This is not an independent review date.
Authorship and responsibility: Antitrust Radar Research Team. Inspect individual roles and disclosure gaps.

Evidence overview

Geographic evidence route

Follow the finding from state screen to source record.

The route preserves 51 statewide screens, eleven annual vintages, the reusable data packet, and the boundary that none is a legal market definition.

Open JSON Run notebook

Declared analytical scope

State screen to annual record to FDIC custody

No legal market node is asserted. Large changes are investigation flags, not causal findings.

Read boundary

Sources, citations, and policy proposals

Public action docket

What government can require next

3 asks

ForFDIC, Federal Reserve, OCC, DOJ, state attorneys general, and state banking agencies

01
Publish durable ownership crosswalks
Release annual machine-readable links among branches, insured institutions, bank holding companies, acquisitions, name changes, and reporting corrections so large geographic shifts can be audited across vintages.
02
Connect state screens to local competition evidence
Pair statewide deposit concentration with reproducible local deposit, lending, pricing, branch-access, digital-service, and customer-switching measures that better reflect where particular customers compete.
03
Investigate outliers before assigning cause
Treat large HHI movements as review flags, then identify whether mergers, entry, exit, ownership reporting, deposit migration, or branch-booking changes explain the observed path.

Evidence still needed

Annual branch-to-holding-company ownership crosswalksMerger, entry, exit, and reporting-change event recordsLocal product-level deposit and lending shares

Open advocacy brief

Reader packet

Reusable

Canonical citation

Antitrust Radar Research Team. (2026, July 20). State Banking Structure, 2015-2025: Stable national concentration can coexist with large state-level shifts. Competition Research Briefs, AR-RB-2026-03 (Version 1.0). Antitrust Radar. https://antitrustradar.org/reports/state-banking-structure-2015-2025

JSON CSV

BibTeX RIS

Briefing packetcite, audit, act Annual state JSON561 exact state-year rows Annual state CSVspreadsheet-ready history Executable notebook572 rows / 6 reconciliation checks FDIC source dossiercustody, method, releases State history atlas51 jurisdiction profiles Local banking screenscounty-level follow-up Action briefpublic oversight asks Methodologylimits and caveats

Source basis

FDIC annual Summary of Deposits branch records for 2015-2025, independently grouped to the reported top bank holding company when available and otherwise to the insured institution.

Source record

State screens

public dataset

Source types

Evidence asks

Read the briefing

Evidence index

Claim to public action

Published Jul 20, 2026 · sources through Jul 19, 2026 · version 1.0 · Current edition

Read / Briefing claim

Start with the authored claim and its analytical boundary.

Start with the aggregate, state paths, and interpretation boundary.

Interpretation boundaryRead the finding with the report's declared market, geography, vintage, and limitations.

Read the analysis

Competition Research Brief / AR-RB-2026-03

Stable aggregate, changing geography

Eleven exact FDIC branch-deposit screens reveal state movement that the national series alone cannot show.

Exact state-year rows: 561; 51 jurisdictions / 11 years
National HHI: 410 to 401; -9 points
Annual state median: 958 to 903; -55 points
State directions: 26 up / 25 down; Median state-specific change +4

01 / Aggregate-9 national HHI

The national screen remained unconcentrated at both endpoints.

02 / Membership5 to 5 high-HHI states

One jurisdiction entered the group and one exited, so the unchanged count hides turnover.

03 / Capacity-29.3% organizations

Reported branches fell 17.9% while nominal deposits rose 70.2%.

Annual structure track

Two stable aggregates, eleven separately observed years

Open annual JSON

Annual June 30 screens

National HHI and the 51-jurisdiction median

Shared 0-1,500 HHI window

Annual state median National aggregateThe annual median is a cross-section, so it need not equal the median change of individual states.

Classification ledger

Seven jurisdictions crossed a descriptive threshold

44 remained in the same class

2015 class to 2025 class, jurisdiction count
2015 to 2025	Unconcentrated	Moderately concentrated	Highly concentrated
Unconcentrated	39	3	0
Moderately concentrated	2	1	1
Highly concentrated	1	0	4

1entered the highly concentrated classDelaware: moderate to high

1left the highly concentrated classNevada: high to unconcentrated

7crossed any classification thresholdThreshold crossing is descriptive, not a legal conclusion

Largest increases

2015 to 2025 HHI movement

01
Delaware1,808 to 4,967 / Moderately concentrated to Highly concentrated
+3,159
02
District of Columbia1,313 to 1,739 / Unconcentrated to Moderately concentrated
+426
03
Ohio843 to 1,094 / +4.6 pts leader share
+251
04
Connecticut1,085 to 1,283 / -1.7 pts leader share
+198
05
Montana971 to 1,158 / +4.4 pts leader share
+187
06
Massachusetts1,461 to 1,637 / Unconcentrated to Moderately concentrated
+176

Largest declines

2015 to 2025 HHI movement

01
Nevada4,517 to 1,462 / Highly concentrated to Unconcentrated
-3,055
02
Minnesota2,282 to 1,459 / Moderately concentrated to Unconcentrated
-823
03
Alaska3,383 to 2,678 / -10.6 pts leader share
-705
04
New Mexico1,066 to 761 / -7.1 pts leader share
-305
05
New Hampshire1,379 to 1,106 / -1 pts leader share
-273
06
Arizona1,753 to 1,498 / Moderately concentrated to Unconcentrated
-255

System capacity

Fewer reported branches and organizations, more nominal deposits

National aggregates / 2015-2025

Reported branches-17.9%

89.7K 73.6K

-16,090 locations

Grouped organizations-29.3%

5.9K 4.2K

-1,732 organizations

Nominal deposits+70.2%

$10.6T $18.0T

Not inflation adjusted

Branch count, organization count, deposits, HHI, and leading share answer different structural questions. Their directions should not be collapsed into one competition score.

Reproduction packet

Rebuild the state field, national ledger, and endpoint findings

The executable packet reconciles 561 state-year observations and 11 national rows to the published brief. It checks published aggregates, not an independent rebuild from raw FDIC branch records.

Run notebook

Input register572 exact rows / one FDIC source

01
State-year field561 rows / 51 jurisdictions / 2015-2025
JSON CSV
02
National annual ledger11 rows carried separately in the same packet
JSON
03
Source custodyAnnual Summary of Deposits / grouped ownership rule
Dossier

Reconciliation gate6 checks

01
The public packet returns exactly 561 state-year rows and 11 national annual rows across 2015-2025.
02
Every year contains 51 unique jurisdiction codes, and every jurisdiction contains eleven unique annual observations.
03
HHI and leading-share values stay in range while branch, organization, and nominal-deposit totals remain positive.
04
Annual state-median and national benchmark fields reconcile to the independently grouped state and national rows.
05
The 2015-2025 endpoint calculation reproduces 26 increases, 25 declines, seven class changes, and the published aggregate anchors.
06
Every state row retains the single FDIC source ID plus observatory, publication, and research-question handoffs.

Table of contents

1.Executive summary
2.Research map
3.Evidence handoffs
4.Methods and limits
5.Source register
6.Public action memo

Evidence ledger

Executive summary

Across eleven annual June 30 FDIC Summary of Deposits screens, national branch-deposit HHI moved from 410 in 2015 to 401 in 2025, while the annual median across 51 jurisdictions moved from 958 to 903. Those aggregate shifts mask substantial geographic variation: 26 jurisdictions recorded higher HHI and 25 recorded lower HHI. Seven crossed a descriptive concentration classification. Five jurisdictions were highly concentrated at both endpoints, but Delaware entered that set while Nevada exited it. The national reported branch count fell 17.9 percent and the grouped organization count fell 29.3 percent, while nominal reported deposits rose 70.2 percent. These screens identify where structure changed; they do not establish why it changed, define a legal banking market, or measure every banking product.

410 to 401

national branch-deposit HHI

-9 points across eleven annual June 30 screens.

FDIC national aggregate

958 to 903

annual 51-state median HHI

-55 points; this cross-sectional median is distinct from the median state-specific change.

State history model

26 / 25

jurisdictions higher / lower

7 jurisdictions crossed a descriptive concentration threshold between the endpoints.

State change field

-29.3%

change in grouped organizations

Reported branches changed -17.9% while nominal deposits changed +70.2%.

National capacity track

Research map

What this briefing connects

Stable aggregates
State change map
Classification transitions
System capacity
Methodology and limits

Source basis

FDIC annual Summary of Deposits branch records for 2015-2025, independently grouped to the reported top bank holding company when available and otherwise to the insured institution.

Bounded geography

State screens point to deeper evidence; they do not define a market.

State history atlas

Inspect all 561 jurisdiction-year rows

Open route

Local banking screens

Move from states to county evidence

Open route

FDIC source dossier

Audit custody, method, and releases

Open route

Methodology and limits matter

These annual rows are statewide screens of FDIC Summary of Deposits branch balances, grouped to the reported top bank holding company when available and otherwise to the insured institution. State boundaries are not legal banking markets, deposits are not every banking product, and changes can reflect ownership reporting or branch booking as well as competitive entry, exit, or consolidation. Deposit values are nominal.

Source basis

FDIC annual Summary of Deposits branch records for 2015-2025, independently grouped to the reported top bank holding company when available and otherwise to the insured institution.

Source register

1 cited public record

01 / 1

Inspect source

public dataset2025

Source 01

2025 Summary of Deposits

Federal Deposit Insurance Corporation

Federal Deposit Insurance Corporation, 2025 Summary of Deposits, branch-level public API records as of June 30 2025.

Annual branch-level deposits for FDIC-insured institutions as of June 30 2025 with institution state and reported bank holding company identifiers.

Accessed: Jul 19, 2026
Custody: Public federal government dataset

Research actions

Audit FDIC source View methodology Browse geographies

Public action memoNear-term

What public institutions should do next

Public banking oversight should use annual statewide branch-deposit screens to locate structural change, then test those signals with local market, ownership, product, pricing, entry, and access evidence before drawing enforcement conclusions.

Audience

FDIC, Federal Reserve, OCC, DOJ, state attorneys general, and state banking agencies

1Publish durable ownership crosswalksRelease annual machine-readable links among branches, insured institutions, bank holding companies, acquisitions, name changes, and reporting corrections so large geographic shifts can be audited across vintages.

2Connect state screens to local competition evidencePair statewide deposit concentration with reproducible local deposit, lending, pricing, branch-access, digital-service, and customer-switching measures that better reflect where particular customers compete.

3Investigate outliers before assigning causeTreat large HHI movements as review flags, then identify whether mergers, entry, exit, ownership reporting, deposit migration, or branch-booking changes explain the observed path.

Evidence needed

Annual branch-to-holding-company ownership crosswalksMerger, entry, exit, and reporting-change event recordsLocal product-level deposit and lending sharesPrices, fees, service quality, switching, and branch-access outcomesInflation-adjusted and deposit-category context

Connect to advocacy playbooks

Policy claims are framed as public-interest asks, not legal conclusions. Each ask should be read with the report’s source basis and limitations.