Where Saved Money Actually Lives

When you deposit money into a savings account, you are lending it to the bank. The bank uses that money — loaning a portion of it to other customers as mortgages and car loans — and pays you interest in exchange for the use of your funds. Deposits at FDIC-insured banks are protected up to $250,000 per depositor, per bank, so this is a very low-risk loan to make.

1. 1
   You deposit $100

   It's federally insured up to the FDIC limit, and it's still legally yours in full, on demand.

2. 2
   The bank keeps a slice, lends out the rest

   As mortgages, car loans, and business credit — deposits like yours are the raw material behind nearly every other loan the bank makes.

3. 3
   Borrowers pay the bank interest

   A mortgage might run 6-7%, an auto loan more, a carried credit card balance far more. This is where a bank's revenue actually comes from.

4. 4
   The bank pays you a cut of that spread

   The APY on your account is a fraction of what the bank earns on your money, in exchange for you agreeing not to need all of it back with no notice.

APY — annual percentage yield — is the rate a bank advertises, and it already accounts for compounding: interest earning interest on itself throughout the year. The interest rate is the raw, un-compounded number; APY is what that same rate turns into once compounding is applied, which is why it's the number that actually belongs on a comparison.

Watch the same 4% nominal rate produce three different balances on $10,000, purely from how often it compounds:

Two accounts both said to pay “4%” can pay meaningfully different amounts if one compounds daily and one compounds annually — APY is the number that makes them comparable, because it's already the actual yearly return, not the raw rate before compounding is folded in.

A balance can grow every month and still be losing value. What matters isn't the nominal return printed on the statement — it's the real return, the nominal return minus inflation, which measures what the balance can actually buy.

Take $10,000 sitting in a checking account paying 0.01% APY, with inflation running at 3% for the year. The account earns about $1. The same $10,000 needs roughly $300 more just to buy what it bought twelve months earlier. The balance grew by a dollar and lost about $299 of real purchasing power in the same year. Move the same $10,000 into an account paying 4.5% APY and it earns about $450 — a real gain of roughly $150 once that same 3% inflation is subtracted out.

A typical checking account pays close to nothing — often 0.01% APY. A high-yield savings account, usually offered by an online-only bank with lower overhead than a branch network, can pay hundreds of times that rate. On a $10,000 balance, the difference between 0.01% and 4.5% APY is roughly $449 a year — for holding the exact same cash, doing nothing differently except which account it sits in.