European stocks reversed their earlier losses to end the day higher, as the race for the White House remained too close to call.
London's FTSE index had gained 1.7%, while the Paris CAC was up 2.4% and the Frankfurt DAX climbed 2% higher by the end of trading today.
Dublin's ISEQ index was also higher, gaining 0.7%, with shares in CPL Resources soaring 34.5% after it said it had agreed to a takeover deal from Japanese firm Outsourcing.
US markets also opened higher today, although investors remained worried about the prospect of a contested result.
The Dow Jones rose 2.9% by early afternoon there, while the S&P 500 was 3.4% and the Nasdaq Composite jumped 4.5%.
Adding to uncertainty, Trump falsely claimed that he had won the US election, and said that "they" were trying to steal the election, without providing evidence.
He said he would go the US Supreme Court to fight for the win if needed.
Earlier this week, money managers had bet on a clear victory for Biden in the election, boosting European equities, as investors anticipated better trade ties with Washington and more economic stimulus for the coronavirus-hit US economy.
Asian markets were mixed this morning as traders tracked results of the US presidential election, but investors were on edge over worries that the outcome might not be as clear-cut as hoped.
Tokyo's Nikkei index closed 1.7% higher, but the Hang Seng index in Hong Kong dipped 0.2%.