The Dow Jones Industrial Average shed over 700 points during trading on Thursday.
The significant dive came on the same day President Donald Trump signed an executive order implementing new tariffs on at least $50 billion of goods imported from China. The move sparked investor fears of a global trade war involving the two largest economies on earth.
The Dow plunged 724 points to close Thursday at 23,958, roughly a three percent dip. In terms of points, it is the fifth largest daily point loss in the index's 122 year history.
Four of the top 10 worse daily point losses have occurred in the past two months. On Feb. 5, the Dow dropped 1,175, the worst of all time.
Trump said the tariff specifically targeting China was because Chinese companies were stealing the intellectual property of Americans.
"We have a tremendous intellectual property theft situation going on," he said as he signed the order.
Chinese officials immediately threatened to take retaliatory trade actions.
"The damage will be real, it will probably be substantial, and it will mount over time," Brad McMillan, the chief investment officer for analyst firm Commonwealth Financial Network, said in a note to his clients. "For companies that sell to China, or indeed any country outside the U.S., the effects are likely to be negative—which is why markets are reacting again. Even the best-case results would still be worse, economically, than where we are now."
The losses were especially acute for companies like Boeing and Caterpillar that export a lot of products abroad. Caterpillar stock fell almost six percent to close Thursday at $146.90, while Boeing stock dropped over five percent to close at $319.61.
The S&P 500 index dropped 68 points to close at 2,644 points, a 2.5 percent decrease. The Nasdaq fell 2.4 percent, or 179 points, to close at 7,167 points.