"Why do interest rates change? It is important to realize that there is not one interest rate, but many interest rates! Interest-rate movements are based on the simple concept of supply and demand. If the demand for credit (loans) increases, so do interest rates. This is because there are more buyers, so sellers can command a better price, i.e. higher rates.

If the demand for credit reduces, then so do interest rates. This is because there are more sellers than buyers, so buyers can command a lower better price, i.e. lower rates. When the economy is expanding there is a higher demand for credit, so rates move higher, whereas when the economy is slowing the demand for credit decreases and so do interest rates.