How does fractional banking work? (And why fractional operators should care)
Fractional reserve banking explained simply — and why fractional CFOs and operators need to understand the basics of how their clients' deposits actually move.
Most people Googling "how does fractional banking work" want a clean explanation of fractional reserve banking — the system that lets banks lend out most of the money you deposit. If you advise companies on cash, you should know this cold.
The core mechanic
When you deposit $100 at a bank, the bank doesn't lock it in a vault. It keeps a small reserve (historically 10%, currently 0% in the US since 2020) and lends out the rest. That loan becomes a deposit somewhere else, which gets lent out again, and so on.
The result is that one deposited dollar can support multiple dollars of credit in the broader economy. This is the "money multiplier."
Why it works (most of the time)
The system relies on the statistical fact that depositors don't all withdraw at once. Banks manage liquidity, regulators set capital requirements, and central banks act as lender of last resort.
When confidence cracks — Silicon Valley Bank, Credit Suisse, every prior bank panic — the model breaks fast. A bank can be fundamentally solvent and still die in a 36-hour run.
What this means for operators advising clients
FDIC insurance covers $250K per depositor per insured bank per ownership category. Companies with $5M of operating cash sitting in one account at a regional bank are taking real, uncompensated risk.
The standard 2026 playbook: sweep operating cash above the FDIC limit into a brokerage account holding short-dated Treasuries or a government money market fund, keep working capital in 2-3 banks, and revisit the policy quarterly.
Reserve requirements vs. capital requirements
Two different rules. Reserve requirements (now 0% in the US) govern how much cash a bank must hold against deposits. Capital requirements (Basel III, CCAR for large banks) govern how much equity a bank must hold against its assets. The capital regime is what actually constrains lending today.
The takeaway for fractional CFOs
You don't need to be a banking economist. You do need a clear, written cash management policy for every client — diversified counterparties, FDIC-aware structuring, and a yield-on-idle-cash plan. "It's just sitting at SVB" is no longer an acceptable answer.
About how does fractional banking work
Is fractional reserve banking risky?+
Systemically, yes — it's why we have central banks and deposit insurance. For an individual depositor staying under FDIC limits, the risk is essentially zero in the US.
What's the current US reserve requirement?+
0%, as of March 2020. The Fed eliminated reserve requirements during COVID and has not reinstated them. Liquidity is now governed primarily through capital and liquidity coverage ratios.