Money markets are short-term lending markets where banks, governments, and large companies borrow and lend cash for periods ranging from one day to one year

A money market is not a place you walk into. It is a system—mostly electronic—where institutions move large sums of cash back and forth on very short notice. When a bank needs cash for a few days, it borrows from another bank or from a money market fund. When the U.S. Treasury needs to borrow for three months, it sells a Treasury bill in the money market. The whole point is speed and safety: money moves in and out quickly, and the loans are backed by rock-solid collateral or by the borrower's reputation.

You do not participate in the money market directly. Instead, you own a piece of it through a money market account or money market fund at your bank or brokerage. That account holds a collection of short-term loans—Treasury bills, commercial paper from large companies, certificates of deposit from other banks. The fund manager buys and sells these loans constantly, and you earn interest on your share of the earnings.

Key Takeaways

  • Money markets are wholesale lending systems where institutions borrow and lend cash for less than one year, not retail banking products you access directly.
  • The securities traded in money markets—Treasury bills, commercial paper, and banker's acceptances—are short-term, low-risk, and highly liquid.
  • Money market accounts at your bank and money market funds at a brokerage are two different products that both give you exposure to money market returns.
  • Interest rates in money markets move with the Federal Reserve's policy rate and change constantly, so your earnings shift month to month.
  • Money market funds are not insured by the FDIC, but money market accounts at banks are insured up to $250,000 per depositor.

The four main securities traded in money markets

Treasury bills are short-term loans to the U.S. government. You lend the Treasury money for 4 weeks, 13 weeks, or 26 weeks, and the government pays you back with interest. Treasury bills are considered the safest investment in the world because they are backed by the full faith and credit of the U.S. government.

Commercial paper is a short-term loan to a large corporation. Apple or Microsoft might issue commercial paper to borrow cash for a few months at a lower rate than a bank loan would cost. The company promises to pay back the loan plus interest on a specific date. Money market funds hold commercial paper from companies with strong credit ratings, which keeps the risk low.

Certificates of deposit (CDs) are time deposits issued by banks. A bank borrows your money for a fixed period—usually three months to one year in the money market—and pays you a set interest rate. If you hold a CD to maturity, you get your full principal back plus the agreed interest.

Banker's acceptances are less common but work like this: a company needs to pay a supplier overseas, so it asks its bank to may provide the payment. The bank writes a may provide (the acceptance) and the company can sell that may provide in the money market to raise cash immediately. The buyer of the acceptance holds it until maturity and collects the payment from the bank.

How money market accounts differ from money market funds

A money market account is a hybrid product offered by banks. It works like a savings account—you deposit cash, earn interest, and can withdraw money—but the bank invests your deposit in money market securities. Money market accounts are FDIC-insured up to $250,000 per depositor, the same as a regular savings account. Your interest rate is set by the bank and may change, but your principal is protected.

A money market fund is a mutual fund that holds a portfolio of money market securities. You buy shares of the fund, and the fund manager buys and sells Treasury bills, commercial paper, and CDs to keep the portfolio aligned with the fund's goals. Money market funds are not FDIC-insured, but they are regulated by the Securities and Exchange Commission (SEC) and required to hold only very short-term, high-quality securities. If the fund manager does their job well, the risk is low—but it is not zero.

The practical difference: a money market account is safer because it is insured, but a money market fund may offer a higher interest rate because it carries slightly more risk. A money market account is easier to access—you can withdraw cash like a savings account—while a money market fund may take a day or two to settle.

Why interest rates in money markets move constantly

Money market interest rates are set by supply and demand, not by a bank or the government. When banks need cash urgently, they offer higher rates to borrow it. When cash is plentiful, rates fall. The Federal Reserve influences money market rates by setting its policy rate—the rate at which banks lend to each other overnight. When the Fed raises its policy rate, money market rates rise. When the Fed cuts rates, money market rates fall.

This means your earnings on a money market account or fund change constantly. If you earn 4.5% one month and the Fed cuts rates, your rate might drop to 4.2% the next month. You do not lock in a rate the way you do with a CD. The trade-off is flexibility: you can move your money without penalty, and you stay invested in whatever the current market rate is.

The role of the Federal Reserve in money markets

The Federal Reserve does not run the money market, but it sets the conditions that make it work. The Fed's policy rate is the interest rate at which banks lend reserve balances to each other overnight. This rate influences every other rate in the money market because banks use it as a benchmark. If the Fed raises its policy rate, banks raise the rates they charge for commercial paper and other short-term loans. If the Fed cuts rates, money market rates fall across the board.

The Fed also acts as a backstop during crises. If money markets freeze up—if banks stop lending to each other because they are afraid of default—the Fed can inject cash directly into the system or lend to banks at favorable rates to get lending moving again. This happened in 2008 and again in 2020, and it prevented a complete collapse of short-term lending.

Who uses money markets and why

Large institutions use money markets to manage their cash. A corporation might have $50 million in cash that it does not need for three months, so it buys commercial paper or Treasury bills to earn interest instead of letting the cash sit idle. A bank might borrow overnight in the money market to cover a temporary shortfall in reserves. A pension fund might hold money market securities as a safe place to park cash between stock and bond purchases.

Individual investors use money markets through money market accounts and money market funds. These products let you earn interest on cash you need to keep liquid—money you might need in the next few months or that you are saving for a specific goal. Money market accounts are popular for emergency funds because they are insured and you can withdraw cash quickly. Money market funds are popular with investors who want slightly higher returns and are willing to accept that the fund is not FDIC-insured.

Money market rates compared to other savings products

Money market accounts typically pay more interest than regular savings accounts because the bank invests your deposit in higher-yielding securities. However, money market accounts usually pay less than a CD of the same length because you can withdraw cash anytime without penalty. A CD locks your money in for a fixed term—say, six months—and pays you a may provide rate. A money market account lets you withdraw anytime, so the bank pays you less to compensate for that flexibility.

Money market funds may pay slightly more than money market accounts because they are not FDIC-insured and can hold a wider range of securities. However, the difference is usually small—a fraction of a percent. The choice between them depends on whether you value the insurance and simplicity of a bank account or the potential for slightly higher returns from a fund.

Frequently Asked Questions

Can I lose money in a money market account or fund?

A money market account at a bank is FDIC-insured, so you cannot lose your principal. A money market fund is not insured, but it is required to hold only very short-term, high-quality securities, so losses are rare. However, if a major borrower defaults or interest rates move sharply, a money market fund's value can fluctuate slightly.

How often does the interest rate on a money market account change?

Banks can change money market account rates anytime, and many do so monthly or quarterly. The rate you earn depends on what the bank is paying, which depends on what money market rates are doing. Check your account statement or call your bank to see your current rate.

What is the minimum deposit for a money market account?

Minimum deposits vary by bank. Some banks have no minimum, while others require $2,500 or $10,000 to open a money market account. Check with your bank for its specific requirements.

Are money market funds safe?

Money market funds are regulated by the SEC and required to hold only short-term, high-quality securities, which keeps risk low. However, they are not FDIC-insured. During the 2008 financial crisis, one major money market fund "broke the buck"—its value fell below $1 per share—but this is extremely rare.

Can I use a money market account as an emergency fund?

Yes. Money market accounts are FDIC-insured, earn interest, and let you withdraw cash quickly. They are a good choice for emergency funds because your money is safe and accessible, and you earn more interest than in a regular savings account.