Asian markets tumble amid tight US presidential race

Asian stock markets are volatile on Wednesday as the US election results so far indicate a tight race for the presidency.

Asian markets are the only ones trading as the polls come in. In early trade, Japan's Nikkei 225 was 1% higher while Australia's ASX 200 and South Korea's Kospi were both 0.3% up.

Hong Kong's Hang Seng opened 1% lower while the Shanghai Composite was flat.

Earlier Wall Street and European markets closed higher, but the gains were small suggesting caution.

The Mexican peso has seen some of the most notable fluctuations, swinging wildly against the dollar, despite surging to a two-month high earlier.

The Mexican currency's movements are seen by many in the market as a good indicator of the election's likely outcome, with an upward movement suggesting Hillary Clinton is ahead.

Analysts said the number of shares being traded was lower than normal, indicating investors are still uncertain about the result.

"2016 has been a year full of surprises. Don't forget the markets priced in a Remain win in the Brexit referendum and got it wrong," said Nigel Green, chief executive of deVere Group.