Despite a 40.6% YoY increase in net interest income during 2026Q3, the bank's net interest margin remains compressed at 0.8%, reflecting persistent funding cost pressures.
| Net Interest Income | 7.82M | 6.04M | 5.84M | 6.7M | 6.21M | 5.39M | 4.55M | 0 |
| NII Growth % | 151.06% | 3.47% | -12.83% | 7.89% | 15.14% | 18.48% | - | - |
| Net Interest Margin % | 3.14% | 2.53% | 2.66% | 2.81% | 2.82% | 2.52% | 2.67% | 0% |
| Interest Income | 11.43M | 9.55M | 9.43M | 8.98M | 7.16M | 6.48M | 5.91M | 0 |
| Interest Expense | 3.61M | 3.51M | 3.59M | 2.28M | 947.77K | 1.09M | 1.36M | 15K |
| Loan Loss Provision | 93K | -93.83K | -190K | 0 | 0 | 0 | 150K | -1.38M |
| Non-Interest Income | 779.21K | 748.92K | 726.02K | 1.3M | 1.04M | 1.81M | 925.74K | 6.66M |
| Non-Interest Income % | 6.38% | 7.27% | 7.15% | 12.66% | 12.69% | 21.79% | 13.55% | 100% |
| Total Revenue | 12.21M | 10.3M | 10.16M | 10.28M | 8.2M | 8.29M | 6.83M | 6.66M |
| Revenue Growth % | 89.95% | 1.41% | -1.19% | 25.4% | -1.12% | 21.31% | 2.56% | - |
| Non-Interest Expense | 7.21M | 6.87M | 7M | 5.88M | 5.48M | 5.35M | 4.82M | 4.43M |
| Efficiency Ratio | 59.07% | 66.74% | 68.94% | 57.24% | 66.82% | 64.51% | 70.56% | 66.42% |
| Operating Income | 1.29M | 10.89K | -246.1K | 2.12M | 1.77M | 1.85M | 505.48K | 452.42K |
| Operating Margin % | 10.59% | 0.11% | -2.42% | 20.59% | 21.62% | 22.32% | 7.4% | 6.79% |
| Operating Income Growth % | - | 104.42% | -111.63% | 19.45% | -4.25% | 266.14% | 11.73% | - |
| Pretax Income | 1.29M | 10.89K | -246.1K | 2.12M | 1.77M | 1.85M | 505.48K | 452.42K |
| Pretax Margin % | 10.59% | 0.11% | -2.42% | 20.59% | 21.62% | 22.32% | 7.4% | 6.79% |
| Income Tax | 192.21K | -31.55K | -59.11K | 444.74K | 437.38K | 477.72K | 87.61K | -880.19K |
| Effective Tax Rate % | 14.86% | -289.76% | 24.02% | 21.01% | 24.68% | 25.81% | 17.33% | -194.55% |
| Net Income | 1.1M | 42.45K | -186.99K | 1.67M | 1.33M | 1.37M | 417.87K | 1.33M |
| Net Margin % | 9.02% | 0.41% | -1.84% | 16.27% | 16.28% | 16.56% | 6.11% | 20% |
| Net Income Growth % | 139.33% | 122.7% | -111.18% | 25.27% | -2.79% | 228.59% | -68.64% | - |
| Net Income (Continuing) | 1.1M | 42.45K | -186.99K | 1.67M | 1.33M | 1.37M | 417.87K | 1.33M |
| EPS (Diluted) | 0.40 | 0.02 | -0.12 | 1.08 | 0.85 | 0.88 | 0.26 | 0.56 |
| EPS Growth % | 36.46% | 112.83% | -111.11% | 27.06% | -3.41% | 238.46% | -53.57% | - |
| EPS (Basic) | - | 0.02 | -0.12 | 1.08 | 0.85 | 0.88 | 0.26 | 0.56 |
| Diluted Shares Outstanding | 2.74M | 2.76M | 1.49M | 1.54M | 1.56M | 1.56M | 1.62M | 2.38M |
High Operating Expense Ratio
As reported in recent quarterly filings, Marathon Bancorp achieved a significant NII expansion, with growth reaching 40.6% YoY in 2026Q3, suggesting that the bank is successfully scaling its interest-earning assets despite a challenging regional rate environment that has historically constrained its top-line performance.
The recent acceleration in NII suggests that the bank may be successfully deploying capital into higher-yielding local commercial loans. Investors should monitor whether this growth is sustainable or if it reflects a temporary surge in loan originations that may face future credit headwinds.
Based on the provided financial data, MBBC's net interest margin has remained stagnant at 0.8% throughout 2026, indicating that the bank continues to struggle with funding cost pressures that offset the benefits of its recent loan volume growth and asset repricing efforts.
The inability to expand NIM beyond 0.8% suggests that the bank's deposit beta remains elevated, likely due to competitive pressures in the Wausau market. This margin profile appears to limit the bank's ability to generate meaningful pre-provision net revenue, leaving little room for error in credit underwriting.
According to the latest income statement data, the efficiency ratio improved to 52.3% in 2026Q3, yet the bank's historical volatility in this metric suggests that Marathon Bancorp has not yet achieved the necessary scale to effectively leverage its fixed-cost base against its revenue stream.
While the recent improvement in the efficiency ratio is a positive signal, the bank's history of spikes above 100% indicates significant operational fragility. Future profitability will likely depend on the bank's ability to maintain this lower cost-to-income ratio as it continues to grow its loan portfolio.
As evidenced by the fluctuating provision expense, which swung from a $95.0K charge in 2025Q4 to a $40.0K benefit in 2026Q1, Marathon Bancorp's earnings remain highly sensitive to management's credit loss estimates, which complicates the assessment of the bank's true core earnings power.
The frequent use of negative provisions suggests that the bank may be releasing reserves to bolster net income, which warrants further investigation into the underlying health of the loan book. Investors should be cautious of relying on these non-cash adjustments to justify the bank's current valuation.
Quick answers to the most common questions about buying MBBC stock.
Marathon Bancorp, Inc. (MBBC) is profitable, generating $0.0M in net income for the fiscal year ending 2025 with a net profit margin of 0.4%.
Marathon Bancorp, Inc. (MBBC) reported an operating income of $0.0M, resulting in an operating profit margin of 0.1%. This margin reflects the operational efficiency of the business before interest and taxes.
Marathon Bancorp, Inc. (MBBC) generated $6.9M in gross profit for the year, representing a gross profit margin of 66.8%. This demonstrates the company's core pricing power and production efficiency.