Banks profit by lending out the money you deposit, while paying you a smaller interest rate than they charge borrowers

A high-yield savings account makes money for the bank through interest rate spread. When you deposit $10,000 in a HYSA earning 4.5% annual interest, the bank pays you that rate. But the bank then lends that same $10,000 to someone else — a mortgage borrower, a car buyer, a business — at a higher rate, often 6%, 7%, or more. The difference between what they pay you and what they collect from borrowers is their profit.

This spread exists because banks take on risk when they lend. A mortgage borrower might default. A business loan might fail. The interest rate they charge borrowers compensates them for that risk. The rate they pay you is lower because your deposit is insured by the FDIC up to $250,000, so the bank faces almost no risk on their end of the transaction.

The bank's profit margin on your account depends entirely on the interest rate environment. When the Federal Reserve raises its benchmark rate, banks can charge borrowers more, so they can afford to pay depositors more and still keep a healthy spread. When rates fall, banks shrink what they pay you first, because they have less room to profit.

Key Takeaways

  • Banks lend out your deposits at higher rates than they pay you in interest, and keep the difference as profit.
  • Your FDIC insurance means the bank takes almost no risk on your deposit, so they pay you less than they charge borrowers.
  • When the Federal Reserve raises rates, banks can afford to pay higher HYSA rates and still profit; when rates fall, they cut what they pay you first.
  • Online banks often offer higher HYSA rates than traditional banks because they have lower overhead costs and can pass more of their lending profit to depositors.
  • The bank's profit on your account shrinks if you withdraw money frequently, because they cannot lend out funds that are not sitting in the account.

Why online banks pay more than brick-and-mortar banks

Online banks like Marcus, Ally, and American Express Personal Savings typically offer higher HYSA rates than Chase, Bank of America, or Wells Fargo. The reason is cost structure, not generosity. A brick-and-mortar bank pays for thousands of physical branches, tellers, security systems, and local staff. An online bank has one or two data centers and a customer service call center. That difference in overhead is substantial.

Because online banks spend less to operate, they can afford to pay you a larger share of the profit from lending out your deposit. They still make money — the spread still exists — but they pass more of it to you to attract deposits. A traditional bank might lend your $10,000 at 7% and pay you 0.01%, keeping 6.99% as profit. An online bank might lend it at the same 7% and pay you 4.5%, keeping 2.5% as profit. Both are profitable; the online bank just operates on a thinner margin because they have lower costs.

How deposit volume affects a bank's lending capacity

Banks need deposits to lend. The more money customers deposit, the more the bank can lend out, and the more interest income they collect. This is why banks compete aggressively on HYSA rates during periods when deposits are scarce. If a bank needs $500 million in new deposits to meet lending demand, they will raise their HYSA rate to attract it. Once they have enough deposits, they can lower the rate again.

Your individual account matters less than the total deposit base. A bank with $50 billion in deposits can lend out roughly $40 to $45 billion of it (they must hold reserves). If deposits drop to $40 billion, they have less to lend and less interest income, so they may cut HYSA rates to slow withdrawals. This is why HYSA rates fluctuate — they track not just the Federal Reserve's rate, but also how much money the bank needs at any given moment.

The role of reserve requirements and capital rules

Banks cannot lend out every dollar you deposit. The Federal Reserve requires banks to hold a percentage of deposits in reserve — money they cannot lend. These reserve requirements vary by bank size and account type, but they typically range from 0% to 10% of deposits. A bank with $100 million in deposits might be required to hold $10 million in reserve and can lend out $90 million.

Banks also face capital requirements set by regulators. These rules require banks to hold a percentage of their assets in capital (essentially, their own money) to absorb losses if loans go bad. A bank cannot lend out all its deposits even if reserve requirements allow it; capital rules limit how much lending they can do relative to their size. These rules exist to prevent banks from taking on too much risk, but they also limit how much profit a bank can extract from your deposit.

Why banks offer different rates to different account types

A bank might offer 4.5% on a HYSA but only 0.01% on a regular savings account, even though both accounts hold the same type of deposit. The difference reflects how the bank expects you to use the account. A HYSA is designed for money you will not touch often — an emergency fund or short-term savings goal. The bank can count on that money staying in the account for months or years, so they can lend it out with confidence and afford to pay you more.

A regular savings account is treated as more volatile. Customers withdraw from it more frequently, which means the bank cannot reliably lend out the full balance. If the bank lends out $10,000 from a regular savings account and you withdraw $5,000 next week, the bank has to pull that $5,000 back from their lending portfolio, disrupting their cash flow. To compensate for this uncertainty, banks pay less on regular savings accounts.

How interest rate cuts affect bank profitability and what you earn

When the Federal Reserve cuts its benchmark rate, banks face pressure from both sides. Borrowers pay less interest on mortgages and loans, so the bank's lending income shrinks. At the same time, banks compete to keep deposits, so they cannot cut HYSA rates as much as they would like. The spread narrows, and bank profit margins compress.

In this environment, banks often cut HYSA rates faster than they cut borrowing rates, because they need to protect their profit margin. If you see a HYSA rate drop from 5% to 3.5% while mortgage rates only fall from 7% to 5.5%, that is the bank protecting its spread. The bank's profit on your account fell, but their overall profitability on lending stayed roughly the same.

The relationship between HYSA rates and money market conditions

HYSA rates do not move in isolation. Banks set rates based on what they can earn in the broader money market. If the Federal Reserve's overnight lending rate is 5.5%, banks can earn that rate by lending to each other overnight. To attract your deposit instead of lending overnight, they need to offer you something close to that rate — maybe 4.5% to 5% depending on their cost structure. If overnight rates fall to 2%, HYSA rates fall too, because banks have less incentive to attract deposits.

This is why HYSA rates rose sharply between 2022 and 2023 — the Federal Reserve raised its benchmark rate from near zero to over 5%, and banks passed most of that increase to depositors to attract money. As the Fed held rates steady in 2024, HYSA rates stabilized. If the Fed cuts rates, HYSA rates will fall, because the bank's opportunity cost of paying you interest drops.

Frequently Asked Questions

Do banks lose money if HYSA rates are very high?

No. Banks only offer high HYSA rates when they can earn even more by lending out your deposit. If a bank pays you 5% on a HYSA, they are lending that money at 6.5%, 7%, or higher. They still profit. If rates fall and they can only lend at 5.5%, they will cut your HYSA rate to 2% or 3% to protect their margin.

Why do some banks offer higher HYSA rates than others if they all lend the same way?

Banks have different cost structures, lending portfolios, and deposit needs. An online bank with low overhead can afford to pay more. A bank flush with deposits can afford to pay less. A bank that specializes in mortgages might lend at different rates than one that focuses on business loans. These differences create rate variation across banks.

What happens to the bank's profit if I withdraw my money frequently?

The bank's profit on your account shrinks. If you deposit $10,000 and withdraw $5,000 after two weeks, the bank only earned interest on $5,000 for two weeks, then had to find another borrower for the remaining $5,000. Frequent withdrawals disrupt the bank's lending schedule and reduce their interest income from your deposit.

Can a bank go broke if too many customers withdraw their savings at once?

Yes, if a bank has lent out most of its deposits and cannot quickly convert those loans back to cash. This is called a bank run. FDIC insurance protects your deposit up to $250,000, but it does not prevent the bank from failing. Banks manage this risk by holding reserves and by borrowing from the Federal Reserve's discount window if they need emergency cash.

Do banks make more money from HYSA accounts or checking accounts?

Checking accounts, because banks pay almost no interest on them. A checking account earning 0.01% is far more profitable than a HYSA earning 4.5%, even though the bank lends out both at similar rates. Banks offer high HYSA rates to attract deposits they would not otherwise get; checking accounts are sticky, so banks can pay almost nothing.