County banking markets / WI / 55105
RockWisconsin
FIPS 55105. Branch offices reported to the FDIC Summary of Deposits, June 30 of each survey year, 1994–2025. One of 72 counties in Wisconsin’s 2025 survey.
Concentration, 1994–2025
Branch-count HHI squares each institution’s share of the county’s branch offices; deposit HHI squares its share of county deposits. The bands are the 2010 Horizontal Merger Guidelines classification, the dashed line the 1,800 level above which the Federal Reserve reviews a merger centrally. In 2025 this market is unconcentrated on branches (922) and unconcentrated on deposits (1,068).
Source: FDIC Summary of Deposits | DOJ & FTC, Horizontal Merger Guidelines (2010), section 5.3 | Federal Reserve, Competitive Effects of Mergers and Acquisitions FAQs Both indices computed from the SOD branch rows for this county, June 30 of each survey year. Neither is the Fed's screen HHI: no thrift weighting, no exclusion of specialty and internet banks, no central-booking adjustment. Methodology
Branches and institutions
46 branch offices and 18 institutions in 1994; 35 and 18 in 2025. Deposits booked in the county went from $1.32B to $3.50B, nominal.
Source: FDIC Summary of Deposits FDIC Summary of Deposits, June 30 of each survey year, 1994-2025. Methodology
Who holds the deposits, 2025
Every institution with a branch in the county, ranked by deposits booked here. Both shares are shown because they are the two indices above: squaring and summing the deposit column gives the deposit HHI, the branch column the branch-count HHI.
| # | Institution | Deposits | Deposit share | Branches | Branch share |
|---|---|---|---|---|---|
| 1 | The First National Bank and Trust Company cert 5285 | $578.8M | 16.54% | 7 | 20.00% |
| 2 | BMO Bank National Association cert 16571 | $532.2M | 15.21% | 5 | 14.29% |
| 3 | Johnson Bank cert 20296 | $442.8M | 12.65% | 2 | 5.71% |
| 4 | First Mid Bank & Trust, National Association cert 3705 | $424.7M | 12.13% | 3 | 8.57% |
| 5 | Associated Bank, National Association cert 5296 | $380.4M | 10.87% | 2 | 5.71% |
| 6 | JPMorgan Chase Bank, National Association cert 628 | $266.8M | 7.62% | 2 | 5.71% |
| 7 | Bank of Milton cert 11232 | $181.8M | 5.20% | 2 | 5.71% |
| 8 | Lake Ridge Bank cert 15091 | $139.4M | 3.98% | 1 | 2.86% |
| 9 | First Community Bank cert 11225 | $138.7M | 3.96% | 1 | 2.86% |
| 10 | Old National Bank cert 3832 | $90.7M | 2.59% | 1 | 2.86% |
| 11 | The Bank of Brodhead cert 2455 | $82.8M | 2.37% | 2 | 5.71% |
| 12 | Town Bank, National Association cert 34717 | $64.5M | 1.84% | 1 | 2.86% |
| 13 | U.S. Bank National Association cert 6548 | $48.7M | 1.39% | 1 | 2.86% |
| 14 | The Greenwood's State Bank cert 11623 | $45.7M | 1.31% | 1 | 2.86% |
| 15 | CBI Bank & Trust cert 1552 | $33.6M | 0.96% | 1 | 2.86% |
| 16 | PremierBank cert 5295 | $23.3M | 0.67% | 1 | 2.86% |
| 17 | Farmers and Merchants Union Bank cert 14445 | $21.7M | 0.62% | 1 | 2.86% |
| 18 | Sauk Valley Bank & Trust Company cert 35131 | $2.8M | 0.08% | 1 | 2.86% |
Source: FDIC Summary of Deposits June 30, 2025. Branch rows grouped by FDIC certificate; names as reported to the survey. Deposit share is n/a where the county's total SOD deposits are zero. Methodology
Back to county banking markets, up to Wisconsin, or read the methodology for the two HHI constructions and what they cannot tell you.