JP Morgan's Jamie Dimon says the market is dealing with something it’s never seen before

Central banks around the world are starting to reverse course after a decade of nursing economies back to health by buying up trillions of dollars worth of bonds. The market has never seen this bond-buying activity, called quantitative easing, and has also never witnessed a period of time when it is being reversed. That could mean uncertainty, says J.P. Morgan's Jamie Dimon. Dimon has been consistently optimistic about the strength of the U.S. economy.