Why does the prime so often move up or down with the discount rate?

The prime rate often moves in tandem with the discount rate because the prime rate is typically set by banks in relation to the cost of borrowing from the Federal Reserve, which is influenced by the discount rate. When the Federal Reserve raises the discount rate, it becomes more expensive for banks to borrow, prompting them to increase the prime rate to maintain their profit margins. Conversely, when the discount rate is lowered, banks can borrow more cheaply, leading them to reduce the prime rate. This alignment helps to maintain stability in lending practices and overall economic conditions.