The 7 biggest investment mistakes celebrities make

Clients can be quick to jump on the bandwagon when it comes to investing in whatever's being touted as the "hot new thing," said Morgan.

He recalls one wave of excitement over a series of tech stocks that "never made sense."

"Friends were calling friends, people were bragging at cocktail and dinner parties about how much money they were making," he said. "In the beginning, they were making money. It ended after a year, and it didn't end well."