Biden back as favourite to win election: Online betting sites

The shift came after Biden overtook Trump in the battleground state of Wisconsin with an estimated 89% of the vote tallied so far. Trump has 49% and Biden has 49.3% of vote, according to Edison Research.

British-based Smarkets exchange is giving Biden a 58% chance, while New Zealand-based predictions market PredictIt had Biden at 63%. Trump's chances on Smarkets were sitting at 41% - a massive drop from 80% overnight.

Odds for a Biden win at one point had fallen to less than a third overnight on Tuesday, data from aggregators showed.

The flip in betting markets overnight was mainly "driven by Trump seemingly holding the key swing state of Florida as a result of a very strong showing for him in the Miami-Dade county with a large Cuban population," said Patrick Flynn, political analyst at Smarkets.

Trump earlier falsely claimed victory over Biden with millions of votes still uncounted in a White House race that will not be decided until a handful of states complete vote-counting over the next hours or days.

Bettors on British betting exchange Betfair meanwhile were also giving Biden about 60% chance to win, denting the prospect of a second term for Trump in the White House.