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Since the beginning of the falling rate cycle, growth in commercial interest-bearing (IB) balances has persisted, even though banks have been actively lowering deposit rates. The latest Curinos Quarterly Commercial Deposit Executive Summary found that overall balances were up 2.2% YOY in September 2025.
Growth was concentrated in regional banks, specifically in the top quartiles, likely driven by those looking to grow their commercial businesses, shore up their balance sheets, or both. (Nationals experienced runoff.) The growth accelerated in Q3 during the ramp-up to the latest round of rate decreases (Figure 1).
Figure 1: Avg. YoY & QoQ Commercial Deposit Growth by Bank Size
This year’s gains have been driven entirely by interest–bearing products, especially in Q3, during which MMDA, sweeps and term deposits all saw quarter-over-quarter increases of more than 4%, while all DDA products were essentially flat. Again, regional banks led the charge (Figure 2).
Figure 2: Average Commercial Deposit Growth by Product Type (QoQ)
Source: Curinos Commercial Deposit Analyzer
The trend of IB balance growth appears to be continuing amid the latest rate decreases, especially for MMDA which has dropped an average of 38 bp but has seen a 2.4% increase in balances.
For banks expecting falling rates to produce interest rate savings, understanding this dynamic is critical. Continued remixing from non-interest-bearing to IB will dampen the savings from lowering rates. Banks will need up-to-date market intel, like that provided through Curinos’ Commercial Analyzer, to navigate this cycle and pay the “right” rate to retain or acquire balances on the margin.
