It's been a volatile year for the stock market, and it's not over yet. The S&P 500 closed just above its 2018 low on Tuesday, and both the Dow Jones Industrial Average and the S&P 500 are on pace for the worst December performance since the Great Depression in 1931.
"It's not a safe market. It's a treacherous market," said CNBC's Jim Cramer. "This is the most treacherous market I've seen in a many a year."
Former Federal Reserve chief Alan Greenspan warned investors that it's unlikely that the market will stabilize and then take take off again. Markets could still go up but, he said, "at the end of that run, run for cover."
Still, for the average person, there's no reason to panic. In fact, the No. 1 thing you should do with your money is absolutely nothing, Greg McBride, CFA and chief financial analyst at Bankrate, tells CNBC Make It.
"Individual investors' biggest enemy in a market correction," or when the market is down more than 10 percent from a high, "is going to be themselves," McBride says. "The worst thing you can do is the panic-selling, knee-jerk reaction."
It's natural for the market to have ups and downs, McBride explains. But if you rush and sell the minute a downturn starts, you're left out when stocks rebound a week, month or year later.