Projections show Republican scoring major victories in key states as the race for president edges to a close.
The US dollar has dropped and stocks have plummeted as investors faced the possibility that Republican nominee Donald Trump could win the race to the White House.
As of 04:55 GMT on Wednesday, Trump was leading Democratic rival Hillary Clinton by 23 Electoral College votes, with a tally of 232-209. It takes 270 to win.
US stock futures recoiled more than 4 percent, a loss reminiscent of the market carnage that followed the British vote to leave the European Union in June; while the Mexican peso went into near freefall as Trump secured the key state of Florida, plunging more than 10 percent against the dollar.
The peso has become a touchstone for sentiment on the election as Trump’s trade policies are seen as damaging to its export-heavy economy.
“There’s a lot of panic in the market. It is definitely an outcome it was not expecting,” Juan Carlos Alderete, a strategist at Banorte-IXE told Reuters news agency.
But the story was very different against the safe-haven yen, with the dollar shedding 3 percent to 102.02 yen. The euro gained 1.5 percent to $1.1190.
However, the price of gold, seen as a safe place for investors’ money in times of uncertainty, soared 3.1 percent to $1,313.50 an ounce.
Meanwhile, South Korean authorities were thought to have intervened to steady their currency, and dealers were wondering if central banks globally would step in to calm nerves.
Markets fear a Trump victory could cause global economic and trade turmoil, discouraging the Federal Reserve from raising interest rates in December as long expected, and have tended to favour Clinton as a status quo candidate who would be considered a safe pair of hands at home on the world stage.
With voting completed in more than two-thirds of the 50 US states, the race was still too close to call in Pennsylvania and New Hampshire, states that could be vital to deciding who wins the presidency.