The 2000 election recount proved anything can happen.
But on Election Day 2016, Tina Fordham, chief global political analyst at Citi, said there's one possibility that could really create upheaval even after the votes are counted.
If neither Hillary Clinton nor Donald Trump get the required 270 Electoral College votes, the Republican-controlled House of Representatives would choose the winner, Fordham pointed out Tuesday on "Worldwide Exchange."
That scenario would presumably favor GOP nominee Trump, even though his candidacy has been something of a lightning rod among his party members on Capitol Hill.
Fordham cited voter turnout as another variable to consider, saying crowds at the polls could favor Trump who may have slim paths to the White House.
While polls give the Democratic nominee Clinton a narrow lead nationally, Fordham said she's "more cautious, than consensus," questioning whether the polls can capture the views of marginalized voters.
Other possible disruptions on Fordham's list included a recount, the loser not conceding defeat, or the electoral vote victor not winning the popular vote, which is what happened after the Supreme Court ruled in 2000, giving George W. Bush the victory over Al Gore.
"I'm not discounting the possibility that there's some type of irregularity that delays an announcement before the [Wednesday] market open in Asia, [London] and possibly New York," she said.
Whatever the outcome, Fordham said she expects to see heavy trading in the 48 hours after election.