Financial markets are reacting in the red to the uncertainty
Hillary Clinton is six percentage points ahead of her rival Donald Trump in the latest US election poll - regaining the lead she held before last week's announcement of an FBI probe into the e-mail scandal.
Many polls have shown Mrs Clinton's lead over Republican rival Donald Trump getting smaller since the e-mail controversy reappeared in headlines on Friday.
But the Reuters/Ipsos daily tracking poll released late on Wednesday showed her six percentage points ahead - the same advantage she held before FBI director James Comey's controversial announcement.
Her advantage is even stronger given that a victory on November 8th depends on the Electoral College system.
To win, a candidate needs a majority of 270 votes and, with large states such as New York and California usually going to the Democrats, Mrs Clinton looks likely to get at least 226 votes.
She will also need to do well in swing states such as North Carolina, Virginia, Florida, Ohio, Arizona and Iowa.
Mr Trump, on the other hand, has a tougher ride to the White House.
He looks likely to win just 180 votes, leaving him relying even more heavily on those swing states.
Florida - or, more specifically, its 29 electoral votes - has been a major focus in the campaign and a RealClearPolitics average of polls there puts Mr Trump just 0.7% ahead .
And it was Florida where Mr Trump was campaigning on Wednesday, projecting a confident exterior, telling supporters in Pensacola: "It's feeling like it already, isn't it?".
He added: "We've got to be nice and cool, nice and cool. Alright, stay on point, Donald, stay on point.
"No sidetracks, Donald, nice and easy."
The financial world was not taking the possibility of a Trump win quite as calmly, however.
Mrs Clinton is favoured by financial markets, seen as a candidate who would maintain the status quo, inspiring stability.
But Mr Trump's views on foreign policy, trade and immigration appear to prompt the uncertainty that puts investors on edge.
Stocks around the world fell on Wednesday, along with the US dollar and oil, while safe havens such as gold and currencies including the euro, yen and the Swiss franc gained strength.
The Dow, S&P 500 and the Nasdaq 0.93% were all down in Wednesday trading.
Chris Weston, chief market strategist at broker IG Research, said: "Despite all the thoughts about central bank policy changes, improving inflation trends and ever-changing economics, politics dominates markets above all else."
Mr Trump was not deterred, however, and told his supporters in Florida that Mrs Clinton was "totally unhinged".
Mrs Clinton, speaking at a rally in Las Vegas, said Mr Trump was "out of his depth".
She added: "He doesn't have a clue."