Security Bank Midwest
Tyndall, South Dakota, Bon Homme County
$304M in total assets, the 2,482nd largest of 4,309 US banks and 29th of 58 headquartered in South Dakota.
- FDIC certificate
- 485
- Established
- 1932
- Owned by
- Midwest Bancshares Inc
- Primary regulator
- FDIC
- Website
- www.sbmidwest.bank
At a glance
Compared with 24 banks headquartered in South Dakota with $100 million to $1 billion in assets, as of June 30, 2026.
| Measure | This bank | Percentile | Peer range, middle 90% | Peer median |
|---|---|---|---|---|
| Total assets | $304M | 62% | $253M | |
| Loans | $216M | 58% | $165M | |
| Deposits | $239M | 62% | $218M | |
| Return on assets | 0.74% | 12% | 1.66% | |
| Net interest margin | 3.55% | 38% | 3.79% | |
| Efficiency ratio | 76.4% | 92% | 53.9% | |
| Equity to assets | 9.39% | 33% | 10.43% | |
| Loans to deposits | 90% | 65% | 82% |
Growth
Total assets grew 3.7% a year over the last 5 years and 6.6% a year over 10 years, without acquisitions.
Acquisitions
| Closed | Acquired bank | Assets at acquisition |
|---|---|---|
| Oct 2013 | Commercial Bank of Minnesota Heron Lake, MN, an affiliate under the same holding company | $35M |
| Nov 2012 | Dakota Heritage State Bank Chancellor, SD, an affiliate under the same holding company | $46M |
Where they operate
6 branches in 4 counties.
Largest markets by deposits
| County | Deposits | Market share | Rank |
|---|---|---|---|
| Bon Homme County, SD | $93M | 39.2% | 1 of 5 |
| Turner County, SD | $76M | 23.1% | 2 of 5 |
| Jackson County, MN | $50M | 16.2% | 3 of 6 |
| Lincoln County, SD | $20M | 0.0% | 25 of 26 |
Deposits by branch from the FDIC Summary of Deposits, June 2026. Rank among all banks with branches in that county.
Branch history since 2016
Net gain of 3 branches since 2016 (3 to 6, +100.0%). 3 opened, 0 acquired, 0 closed or sold.
| Period | What happened | Opened or acquired | Closed or sold | Net change | Branches at end |
|---|---|---|---|---|---|
| Start of 2016 | Starting point | 3 | |||
| 2020 | Opened Jackson and Viborg | 2 | 0 | +2 | 5 |
| 2024 | Opened Lennox | 1 | 0 | +1 | 6 |
Balance sheet and earnings
Loans by type
| Type | Share | This bank | Peers |
|---|---|---|---|
| Agricultural | 52% | 29% | |
| Farmland | 26% | 22% | |
| Business (C&I) | 7% | 10% | |
| Commercial real estate | 5% | 14% | |
| 1-4 family residential | 4% | 14% | |
| Multifamily | 1% | 4% | |
| Construction and land | 1% | 3% | |
| Consumer | 1% | 4% | |
| Other | 3% | 1% |
Deposits by type
| Type | Share | This bank | Peers |
|---|---|---|---|
| Other interest-bearing | 41% | 45% | |
| Time deposits | 38% | 37% | |
| Noninterest-bearing | 21% | 18% |
Brokered deposits are 6.9% of deposits (peers 3.0%).
Return on assets
Trailing four quarters, with the peer median.
Credit and capital
| This bank | Peer median | |
|---|---|---|
| Noncurrent loans | 0.40% | 0.16% |
| Net charge-offs, annualized | 0.00% | 0.00% |
| Reserves to loans | 1.37% | 1.27% |
| Leverage ratio | 10.52% | 10.76% |
Noncurrent loans exclude government-guaranteed portions.
Related banks
Similar size in South Dakota
Largest competitors in Bon Homme County, SD
Figures as of June 30, 2026 from the bank's Call Report, FDIC structure and branch data, and the Federal Reserve. Short link: bankingstats.com/security-midwest