While it is true that banks are able to borrow money at historically low interest rates at the moment, the rate at which banks have been able to lend money has also been compressed recently, and the banking industry's profit margin in between those two rates is shrinking. However, in this video, Motley Fool financial analyst Matt Koppenheffer points out that while these shrinking margins are hard for banks across the industry, very low interest rates also mean banks are doing a huge amount of volume in mortgage and mortgage refinance loans, and the fee business from those loans is booming.