Millennials aren’t investing in the markets. Here’s why.

More than 60% of millennials prefer to store their retirement savings in a bank instead of investing, according to a study published by NerdWallet, and financial expert Chris Hogan said that’s because they’re afraid of the stock market.

“People tend to fear what they don’t understand,” Hogan told FOX Business’ Dagen McDowell during an interview on Friday. “And they’re coming off this ride where there was a market shift, or market change, and so now, because of fear, people will just refrain.”

Hogan is trying to educate millennials about the stock market by trying to get them to understand that because of inflation, saving money while not investing is not a good strategy.

“If you don’t outpace inflation, your money is shrinking,” he said. “So it’s scaring me that these millennials are throwing their money in a savings account, and they think everything is going to be OK.”

According to a survey by assisted-living company Aperion Care, 34% of millennials believe they will need $200,000 or less to retire comfortably. But, in order to live off of $40,000 a year, a retiree needs to save about $1.18 million for a 30-year retirement, according to AARP. The average retirement age for millennials is expected to be 72.

“Either way, based on fear, or based on distrust, or based on lack of knowledge, we’re going to have a problem in America,” Hogan said. “We’re going to have an issue, because people are going to have to work much longer.”