Prime Interest Rate and How It Affects You

Two Ways Hikes in the Prime Rate Cost You Money

prime rate recipient
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The prime interest rate is what U.S. banks charge their best customers. These are the businesses and individuals with the highest credit ratings. They received this rate because they are the least likely to default. Banks have little risk with these loans. They're happy to pass these cost savings onto these preferred customers.

The prime rate is the best loan rate available to anyone except other banks. It's also called the prime lending rate, the prime rate, or even just prime. It's currently 4.75%.

How the Prime Rate Is Determined

Banks base the prime rate on the federal funds rate. It's managed by the nation's central bank, the Federal Reserve. It's the rate banks charge each other for special overnight loans. They borrow fed funds from each other to fulfill the Fed's reserve requirement each night.

Banks lowered the prime rate when the Federal Open Market Committee lowered the current Federal Reserve interest rate to a range between 1.5% and 1.75%. The prime rate is three points above the fed funds rate.  The interest rate outlook is for the fed funds rate to remain at 2.0% through 2021.

Other interest rates are determined by Treasury notes. Those include fixed rates for 30-year mortgages, corporate bond rates, and other long-term loans.

Two Ways the Prime Rate Affects You

Banks base most interest rates on prime. That includes adjustable-rate loansinterest-only mortgages, and credit card rates. Their rates are a little higher than prime to cover banks' bigger risk of default. They've got to cover their losses for the loans that never get repaid. The riskiest loans are credit cards. That's why those rates are so much higher than prime. 

The prime rate affects you when it rises. When that happens, your monthly payments increase along with the prime rate. Pay close attention when the Fed is raising the fed funds rate. It means your costs are about to go up.

The prime rate also affects liquidity in the financial markets. A low rate increases liquidity by making loans less expensive and easier to get. When prime lending rates are low, businesses expand and so does the economy. Similarly, when rates are high, liquidity dries up, and the economy slows down.

Prime Rate Versus Libor

Not all banks base their interest rates on the prime rate. International banks and large banks with a lot of foreign customers use the London Interbank Offer Rate. It's the rate banks charge each other for short-term loans. 

The fed funds rate, Libor, and the prime rate move in tandem, according to records from JPMorgan Chase & Co. The prime rate is higher than the three-month Libor rate. That Libor rate is a few tenths of a point above the fed funds rate.

When the rates don't move together, that indicates that something is wrong with the financial markets. For example, Libor rate history shows that in September 2007, the Fed lowered the fed funds rate down half a point. Libor didn't budge, according to records at the Federal Reserve Bank of St. Louis. Banks were afraid of getting subprime mortgage debt as collateral from each other. They kept Libor high to offset this risk. Banks were so afraid to lend to each other that they kept raising Libor even as the prime rate fell. This is illustrated in the chart below.

When the Fed lowered its interest rate from a range between 5.0% and 5.25% to a range of between 4.5% and 4.75% on September 18, 2007, the prime rate also dropped, from 8.25% to 7.75%. But Libor rose from 5.5% to 5.6%. As the Fed continued to lower its rate, the prime also fell. Libor bounced up and down. That indicated the high level of irrational fear between banks. 

On October 8, 2008, when the Fed lowered its rate to a range between 1.25% and 1.5%, the prime rate dropped to 4.5%. Unbelievably, it was barely above Libor, which stubbornly remained at 4.3%. That occurred weeks after the panicked run on money market funds that almost brought the U.S. economy to collapse. This Fed rate cut was part of a coordinated effort among all the world's central banks to shore up the collapsing financial markets. It was only a few days after Congress passed the $700 bank bailout bill. Banks were in a state of sheer panic. The 2008 financial crisis timetable reveals how events led to the worst economic crisis to hit the United States since the Great Depression.

Soon afterward, Libor slowly started returning to normal. When the Fed lowered its rate to zero in December 2008, the prime rate obediently fell to 3.25%. Libor dropped to 2.19%. It took another year before it returned to its typical range, a few tenths of a point above the Fed's rate. ​