S&P 500 and Nasdaq futures were briefly halted after hitting their exchange-set limits of decline Tuesday night. The dollar traded lower against major currencies and gold jumped 5 percent late Tuesday.
If stocks follow the path of futures at their worst levels of the overnight, and major averages fall 5 percent during Wednesday trading, they could see the worst day since August 2011, when Standard and Poor's stripped the U.S. of its AAA rating.
The last time the Dow and S&P 500 fell more than 5 percent was on Aug. 8, 2011, the first trading day after the downgrade. The Dow fell 5.6 percent, and the S&P 500 was down 6.7 percent.
Barclays global equity analyst Keith Parker said he had expected the S&P 500 could trade as to as low as 2,000, based on the probabilities of a Trump win. He said key to how much more it declines will be the kind of comments Trump makes right away and what type of people he surrounds himself with as possible members of his administration. The S&P 500 closed Tuesday up 8 points at 2,139, as markets speculated that Clinton was in the lead.
"Markets would be volatile. Equities would take their cue from confidence indicators — what Trump says, what the GOP leadership does," he said.
The market is expected to unwind gains of the past two days and then some.
"People are scared, and they are looking for some sort of certainty and this is going to take some time to work through that. People are going to want to know who he's going to pick for his Cabinet. I think people are going to freak out. They're going to worry about foreign actors," said Dan Clifton, head of policy research at Strategas.
Clifton said there will be a lot of ripples from the upset. For instance, Fed fund futures odds are likely to shift away from December, as it's less likely the Fed will hike into market turbulence.
One of the biggest concerns about Trump has been his stand on trade. Trump has threatened to break trade agreements with Mexico and build a wall along the border. He also has criticized China.
"For right now, it's not directly a China problem. It's more a trade problem for the rest of the world," said Paul Christopher, head global market strategist at Wells Fargo Investment Institute. Christopher said protectionism is a concern.
With a Trump win, "the main concern is trade. The second main concern is the budget deficit," Christopher said.
Analysts have been divided on whether the Trump sell-off would be a lengthy down trend or result in a quick bounce back, like after Brexit when the U.K. voted in June to leave the euro zone.
Clifton said even with the decline, there could be bargain hunting in some sectors that would do better under Trump. That would include biotech, financials, infrastructure and defense.