The 2020 US Election on Betfair: The race that broke all records

• 100/1101.00 Biden prevails in record-breaking market

• More than £480 million traded on the 2020 US Election

• Get a completely free US election bet on the Betfair Exchange

• Check out our 2024 US Presidential Election Live Blog here

Biden starts the year as a huge outsider

As 2020 began, the world's biggest political event was on the horizon, the US Presidential Election.

You could feel election fever in the air, but few would have predicted the roller-coaster ride for bettors.

Just six weeks into the year - on 12 February to be precise - Bernie Sanders is leading the race to become the Democratic leader and Joe Biden is trading at just shy of 100/1101.00 on the Betfair Exchange to become the President. Those odds mean Biden has just a 1% chance of winning the 2020 US Election.

Fast forward another five weeks and it's all change. On 23 March Biden is on track to take the Democrat nomination and he goes favourite to win the election. He's available to back at around 2.186/5 on the Betfair Exchange, meaning he has a 46% chance of winning.

But he's not favourite for long. The reason. President Donald Trump.

Less than 24 hours after Biden went favourite, Trump is being backed at around 2.0811/10 - the equivalent of 11/102.11 as fractional odds - implying that he has a 48% chance of staying in office for a second term.

Biden wins Democratic nomination

April and May were relatively quiet months with both Trump and Biden taking their turn at the top of the betting market, but June saw a significant move for Biden as he wins the Democratic nomination. On the 5th of the month the former Vice President is backed into 1/12.00 (50% chance of winning) to win the US Election with Trump drifting out to 11/82.38.

And over the next few months Biden starts to pull clear.

As news speculation surrounding President Trump's tax returns grow punters continue to back the Democrat, and on 4 August Biden is available to back at just 8/131.61, implying that he has a 62% chance of winning the US Election. The market gives Trump a 38% chance of winning as his odds drift to 13/82.63.

However, just three weeks later, in what has now become a see-saw battle, both candidates are back to even money (1/12.00) to win the election as the party conventions come to an end.

£1m traded on a single day and £100m matched in total

On 26 August there's still nothing to separate Trump and Biden at the top of the market, but it was a historical day on the Betfair Exchange as the US Election Winner market saw over £1 million traded on it in a single day.

And just one month later, following weeks of momentous election news, the market reaches £100 million matched on it.

The news doesn't slow down in October, with a Covid outbreak in the White House and both candidate's campaigns ramping up. Come the 28th of the month, Biden has again soared clear on the Betfair Exchange and he is back to odds-on at around 4/91.44, implying he has a near 70% chance of winning.

Support for Trump is waning, and he's out to 9/43.25 to stay in office, giving him a 30% chance of winning the election.

Biggest betting event of all time as Election day arrives

October 28 was also a momentous day for Betfair as the betting market reaches £200 million traded, making it the single biggest betting event of all time.

Six days later, the polling stations opened and Biden had eased slightly in the betting to 1/21.50 with Trump the outsider of the pair at 2/13.00.

As the polls closed across America there were good signs for Trump in the sunshine state of Florida and Biden's odds ease again, out to 1.75/7 on the Betfair Exchange at around 01:30 on 4 November.

First Trump then Biden go long odds-on

But just 90 minutes later there's a huge plunge on Trump as news begins to break that Florida looks certain, he had deficits in Texas and Ohio reversed, and he has good early numbers in the Midwest. Trump's price crashes, and from being a 2/13.00 outsider to win the US Election he's now a massive favourite at 1/41.25.

However, the clock ticks to 03:30 and Arizona looks good for Biden, Trump's odds creep out to around 8/131.61. But only briefly. With Iowa, Florida and Texas called for Trump, by 07:30 he's back as a solid 1/21.50 favourite with Biden at 2/13.00.

But then the final swing starts. Although Biden trails in Georgia, Michigan, Wisconsin and Pennsylvania his odds tumble as late voters are trending to go his way. Biden goes marginal favourite at 10:30, and just an hour later his price has shortened again in to 4/71.57 with Trump now the outsider at 7/42.75.

Incredibly, at 11:30 on Wednesday 4 November, over £425 million had been match on the Betfair Exchange US Election market.

By midday Biden is eating into his deficit in the Midwest states, and at 5pm, with wins secured in Michigan and Wisconsin, he hits his lowest price yet and is just 1/51.20 to become President of the United States.

Will 2024 US Election smash the records?

From election night onwards, £131 million was traded within a 24 hour period, taking the total matched on the Betfair Exchange to £480 million.

The 2020 US Election was the race that broke records. In over 20 years of Betfair history there has never been a bigger betting event, and yet just four years later we could be set to break all records again.

The patterns have been largely the same. At the start of the year Kamala Harris was a huge 150/1151.00 outsider to become the next President of the United States before securing the Democratic nomination due to Joe Biden pulling out of the race. She has already been matched at 10/111.91, and with eight weeks remaining before the election, there's barely anything to split Harris and Trump in the market.

At the time of publishing this story, more than £113 million has already been traded on Betfair's US Election markets and that number is expected to rise significantly in the next two months. The 2020 US Election may have broken all records, but the 2024 US Election might end up smashing them again.

Timeline of significant days:

- 12 Feb: Joe Biden is around 100/1101.00 to win US Election
- 23 Mar: Biden goes favourite at 6/52.20 to be the next President
- 24 Mar: Donald Trump goes favourite at 11/102.11 to remain President
- 5 Jun: Biden wins Democratic nomination and is in to 1/12.00 to win election
- 4 Aug: Speculation about Trump's tax returns grow and Biden goes odds-on at 8/131.61
- 4 Aug: On the back of the news Trump drifts out to 13/82.63
- 24 Aug: The party conventions end and both Trump and Biden are back to 1/12.00
- 26 Aug: Over £1 million traded in a single day on the US Election Winner market
- 30 Sep: The market sees over £100m matched on it
- 28 Oct: Support for Biden surges and he's odds-on at 4/91.44 to win
- 28 Oct: At £200m traded, the US Election becomes the biggest single betting event of all time
- 3 Nov: Election day - Joe Biden is 1/21.50 to become President, Donald Trump is 2/13.00
- 4 Nov: In the early hours Trump's numbers are looking good and his price is slashed in to 1/41.25
- 4 Nov: Another huge swing as Biden goes 4/71.57 favourite at around 11:30
- 4 Nov: At the same time, the amount traded on the US Election market passes £425m
- 4 Nov: At 5pm Biden is now red hot favourite at 1/51.20 to become President
- 4 Nov: Over £131m traded within 24 hours with the total amount matched now at £480m

Now read more US Election news, previews and tips here.