The Basic Model — Intermediaries
At their core, banks do one thing: they connect people who have money to spare with people who need to borrow it. They earn money from the difference between the interest they pay depositors and the interest they charge borrowers — the interest rate spread.
This model benefits everyone involved: savers earn interest on their deposits; borrowers get access to capital they need; and the bank earns a profit from the spread between the two rates.
Accepting Deposits
Banks offer various deposit accounts where individuals and businesses can place their money. These deposits form the foundation of the bank’s lending capabilities.
Checking Accounts
Designed for frequent transactions — paying bills, making purchases, receiving payroll. Typically offer low or no interest. Banks earn revenue from transaction fees and by using the deposited funds for lending.
Savings Accounts
Designed to hold money over time. Banks pay depositors interest on savings accounts — typically lower interest than what they charge on loans — and use the pooled deposits to fund their lending operations.
Certificates of Deposit (CDs)
Time-locked deposits that pay higher interest in exchange for agreeing to leave the money untouched for a set period (6 months to 5 years). CDs provide banks with more predictable funding for longer-term loans.
Making Loans
Banks use pooled deposits to make loans to individuals and businesses. Borrowers pay back the loans with interest, which is the primary source of bank revenue.
Mortgages
Loans secured by real estate, typically repaid over 15 or 30 years. The property serves as collateral — if the borrower defaults, the bank can foreclose. Mortgages are one of the largest categories of bank assets.
Consumer Loans
Auto loans, personal loans, and student loans. These carry higher interest rates than mortgages because the collateral (a car, for example) depreciates or may not exist at all for personal loans.
Business Loans
Capital for businesses to invest, expand, hire, or manage cash flow. Interest rates vary based on the business’s creditworthiness, collateral, and the loan term. A primary driver of economic investment.
Credit Cards
Revolving credit lines that charge high interest on carried balances (typically 18–29%). Credit card interest is one of the most profitable loan categories for banks. See Credit.
Fractional Reserve Banking & Money Creation
Banks do not simply lend out the deposits they collect — they actually create money in the process. This happens through a system called fractional reserve banking: banks are only required to keep a fraction of their deposits on hand as reserves, and can lend out the rest.
When a bank makes a loan, it credits the borrower’s account with the loan amount — effectively creating new money in the banking system. This money multiplier effect is how the banking system as a whole creates far more money than exists in physical currency.
This is why bank runs are dangerous: if too many depositors try to withdraw at once, no bank can pay them all simultaneously — deposits have been lent out. The FDIC insures deposits up to $250,000 per account per bank, specifically to prevent bank runs by ensuring depositors do not need to panic.
Risk Management
Banks face two primary types of risk that must be managed continuously:
Credit Risk — Will borrowers repay?
Banks assess the creditworthiness of borrowers before making loans — reviewing credit history, income, assets, and collateral. The interest rate charged on a loan reflects the perceived risk: higher risk borrowers pay higher rates to compensate the bank for the possibility of default. See Credit.
Liquidity Risk — Can we meet withdrawals?
Banks must maintain enough liquid assets (cash and easily convertible assets) to cover day-to-day withdrawal demands, even though most of their assets are tied up in long-term loans. Managing this balance between long-term lending and short-term liquidity is one of the core challenges of banking.
The Federal Reserve & the Discount Window
Banks Can Borrow from the Federal Reserve
Banks can borrow money directly from the Federal Reserve through a process called discount window lending. This serves as a safety net for banks facing temporary liquidity shortages or unexpected issues.
The discount rate is the interest rate the Fed charges banks for this borrowing. It is typically set higher than the federal funds rate (the rate at which banks lend to each other overnight) to discourage routine reliance on Fed borrowing.
The Fed also sets monetary policy by adjusting the federal funds rate — the target rate for overnight lending between banks. When the Fed raises this rate, borrowing costs increase throughout the economy; when it cuts the rate, borrowing becomes cheaper. This is how monetary policy influences inflation, employment, and economic growth.
Facilitating Payments
Beyond deposits and loans, banks provide the infrastructure that makes modern commerce possible:
Payment Processing
Banks enable payments through checks, debit cards, credit cards, ACH transfers, and wire transfers. Every time you swipe a card or send an electronic payment, the banking system processes the transaction — verifying funds, routing the payment, and settling between institutions.
International Transfers
Banks facilitate the movement of money across international borders through SWIFT (Society for Worldwide Interbank Financial Telecommunication) and correspondent banking relationships. International transfers involve currency conversion and compliance with multiple countries’ regulations.
How Banks Make Money
Banks generate revenue from three primary sources — the most important being the spread between what they pay depositors and what they charge borrowers:
Interest Paid to Depositors
- Savings account interest (low)
- CD interest (higher, locked)
- Money market interest
- Checking interest (minimal)
Interest & Fees Collected
- Mortgage interest (4–8%+)
- Auto and personal loan interest
- Credit card interest (18–29%)
- Business loan interest
- Account fees and service charges
- Investment and advisory fees
The difference between the two columns — what the bank earns minus what it pays — is the net interest margin, the primary driver of bank profitability. A bank paying 0.5% on savings accounts while charging 7% on mortgages is earning a 6.5% spread on that capital.
Why Understanding Banks Matters for Your Finances
Banks play a vital role in the economy — facilitating transactions, providing access to credit, and managing the flow of money. Understanding how they work helps you make better decisions about where you keep your money and at what cost.
📈 Interest rates are negotiable context
Banks set rates based on risk and competition. Shopping between institutions — and knowing your creditworthiness — gives you leverage to negotiate better rates on loans and higher yields on deposits.
🌿 Your savings earn the bank money
When your money sits in a low-yield savings account, the bank lends it at a much higher rate and pockets the spread. Understanding this is motivation to ensure your long-term savings are working harder. See Saving.
⚠ FDIC insurance matters
Deposits are insured up to $250,000 per account type per bank. Large balances above this threshold carry real risk if a bank fails. Understand where your money is and whether it is fully insured.
💸 Credit card interest is expensive
At 18–29%, credit card interest is among the highest guaranteed costs any consumer faces. Carrying a balance means you are paying the bank’s most profitable rate. See Credit.
Banks are one tool in a complete financial strategy. For retirement planning, insurance-based products, and alternative investments often provide better returns and more favorable terms than traditional bank products alone. Contact us for a free consultation on building a strategy that goes beyond what banks offer.