Australian shares have plunged to a four-month low and lost $35 billion in value amid a global shock from US election results that have left Donald Trump poised to become the next president of the United States.

Stunned investors sold down Australian stocks on Wednesday during a rollercoaster day where market fortunes rose with early hopes of a win for Democrats runner Hillary Clinton, then plunged as the Republican challenger stormed to strong lead as counting progressed into the night.

The benchmark S&P/ASX200 closed 1.9 per cent lower after gaining more than one per cent in morning trade.

Stocks had plummeted to a deeper intra-day low than was suffered after the shock UK Brexit vote in June but recovered towards the end of trading.


Asian markets joined the rout, with Japan's Nikkei 225 index plunging more than five per cent and Hong Kong's Hang Seng index shedding almost three per cent as their afternoon sessions continued.

Futures trading showed US markets are also poised to open lower, with the Dow Jones futures index 3.7 per cent lower.

At the close of trade in Australia, Mr Trump had secured 244 of the 270 electoral college votes needed to secure the presidency, well ahead of Mrs Clinton's 215.

Bell Direct equities analyst Julia Lee said markets didn't like uncertainty and Trump was seen as an unknown quantity.

"Hillary Clinton is seen as a known candidate, the markets are familiar with her while with Donald Trump, there's a perception he makes policies on the go," Ms Lee said.

All sectors on the ASX closed deep in the red, with the banks, health and energy sectors suffering the biggest declines.

Gold stocks were a bright spot amid a rush to safe-haven investments, with Evolution Mining gaining 11.4 per cent to $2.55 and Newcrest Mining rising 9.8 per cent to $25.35.

In local share news, poker machine maker Aristocrat Leisure fell 89 cents, or 5.9 per cent, to $14.30 following news its chief executive Jamie Odell is stepping down next year.

Seven West Media dropped 3.5 cents, or five per cent, to 67 cents after the company said its full-year earnings will be close to 20 per cent down on the prior year - the lower end of its earlier guidance of between 15 and 20 per cent.

Health insurance giant Medibank Private told shareholders at its annual general meeting that it faces a tough year with revenue growth in the first four months of fiscal 2017 missing its initial expectations.

Shares in Medibank dropped 10 cents, or 3.92 per cent, to $2.45.

Among the few shares to rise on Wednesday was Webjet after the online travel group announced it will sell its Hong Kong and Singapore-focused Zuji business for $56 million.

Webjet's shares gained 43 cents, or 4.6 per cent, to $9.75.


• At 1630 AEDT, the benchmark S&P/ASX 200 index was down 101.2 points, or 1.92 per cent, at 5,156.6 points.

• All Ordinaries was down 103.9 points, or 1.94 per cent, at 5,238.3 points.

• The December share price index futures contract was down 103 points at 5,142 points, with 78,489 contracts traded.

• National turnover was 3.79 billion securities traded, worth $9.3 billion.