Betfair lowers Clinton chances as punters lay money on outsiders

Clinton still occupies the favourite position comfortably as closest rival Donald Trump didn't gain any traction on the Betfair Exchange, with non-runners Joe Biden and Bernie Sanders' odds dropping significantly.

Having held a much higher figure of an 80% chance, the exchange now places her at a more modest 64%.

The Democratic nominee suffered over the weekend both in the polls and in her physical health, as the decision by her campaign not to disclose her pneumonia diagnosis backfired.

"By this point, the market should theoretically be a two-horse race and the percentage likelihood for each candidate should equal 100%," said Betfair spokeswoman Naomi Totten. "But with Joe Biden, Bernie Sanders and Tim Kaine still attracting support in the market, there is clearly a feeling amongst bettors that anything could happen between now and November 6th."

Totten added that there was a record amount of money being bet on the outcome of the election, due to the close race between Clinton and Trump.

"The difference with this election is that the race is seemingly still relatively open, with confidence in both party nominees exceptionally low," she said.