Here’s what Warren Buffett says to do when the market tanks

On Friday, as investors reacted to the possibility of a trade war between the United States and China, the Dow Jones industrial average fell 400 points into correction territory, marking its worst week since January 2016. The Dow dropped a total of 5.7 percent over the week, while the S&P 500 fell 5.9 percent and the Nasdaq composite fell 6.5 percent.

That leaves many investors worried and wondering what to do.

During times of stress and uncertainty, Oracle of Omaha Warren Buffett recommends keeping a level head. In response to wild market fluctuations back in 2016, he told CNBC that buy-and-hold is still the best strategy.

"Don't watch the market closely," he advised those worried about their retirement savings at the time. "If they're trying to buy and sell stocks, and worry when they go down a little bit … and think they should maybe sell them when they go up, they're not going to have very good results."