Bank concentration rose in half the country. Here is where it rose the most.

Fewer banks, fewer branches, the same national number

Between 2015 and 2025 the number of bank holding organizations with FDIC-reported branches fell from 5,919 to 4,187, a 29 percent decline. Branches fell from 89,658 to 73,568, 18 percent. The national deposit HHI barely moved, from 410 to 401, because a national HHI is the wrong instrument: nobody banks nationally.

Measured where people actually bank, the picture is different. Statewide deposit concentration rose in 26 of 51 jurisdictions and fell in 25. Above the 2,500 HHI line of the 2010 merger guidelines, which the 2023 guidelines lowered to 1,800, sit 5 states: Delaware (4,967), South Dakota (4,654), Alaska (2,678), North Carolina (2,626), and Hawaii (2,569).

The states where concentration rose the most

Delaware leads by a distance. Its statewide HHI went from 1,808 to 4,967, and its leading organization, Capital One Financial Corporation, now holds 67.8% of deposits. Most of that jump arrived in 2025, the year Capital One completed its acquisition of Discover, whose bank is chartered in Delaware. It is a real consolidation of two of the largest card issuers in the country, booked in one small state.

The rest of the list is the slower story: consolidation among regional and community banks in Ohio, Connecticut, Montana, Massachusetts, and New York, where the number of organizations fell by 16 to 30 percent and the leader's share edged up.

And where it fell

Nevada went the other way, from 4,517 to 1,462, with Wells Fargo & Company now holding 24.6% of a market that a decade ago had a far more dominant leader. Minnesota and Alaska also fell. Falls are worth listing for the same reason as rises: they show that the direction is not fixed, and that ownership and booking changes can move a statewide number a long way without a single branch changing hands.

Four banks lead 296 counties

Rank the organization with the largest deposit share in each county and four names account for 296 of them: Wells Fargo & Company (119), Truist Financial Corporation (67), JPMorgan Chase & Co. (63), and Bank of America Corporation (47). The national HHI says these banks are not dominant. The county map says they are the largest bank in one county out of every ten.

Reading the county jumps carefully

The counties with the biggest HHI increases are a mix of two things, and it would be dishonest to run the list without separating them. Some are ordinary consolidation: a county with a few banks that lost one to a merger. Others are booking effects: a national bank reports its deposits at a headquarters branch, so a suburban county in Texas or South Dakota shows a near-monopoly that no resident experiences. The rows flagged in the table are the second kind. They are real entries in the FDIC ledger and a real limit of the screen, and we show them so readers can see where the screen stops being about local competition.

What should happen

Bank merger review uses market definitions drawn decades ago and a screening process that has approved essentially every application put before it. The evidence here says the harm, where it exists, is local and cumulative: a branch closure here, an acquisition there, until a county has one bank. We think the banking agencies and the Justice Department should publish the local market definitions they use, screen every application against the county deposit table, and explain in writing when they approve a deal that pushes a county above 2,500 or leaves it with two organizations or fewer.

We also think the annual Summary of Deposits release should come with the FDIC's own concentration screen, so that the public benchmark is the agency's rather than ours.