As we enter the final stretch of the 2024 U.S. presidential election, international betting platforms show former president Donald Trump in an unprecedented position: Leading for the first time after Labor Day.

The Republican candidate, Trump, has a narrow advantage over the Democratic contender, Vice President Kamala Harris, in major betting markets like Betfair Exchange, the largest peer-to-peer betting site in the U.K., and Polymarket, a cryptocurrency-based trading platform. As of 8 a.m. ET Saturday, Polymarket indicated Trump’s likelihood of winning at 51%.

However, this electoral betting, which is not legally permitted in the U.S., contradicts recent polling among American voters:

◾ A fresh YSL News/Suffolk Poll shows Harris ahead with 48% compared to Trump’s 43%, still within the margin of error for the poll. This survey, which includes 1,000 likely voters, was conducted via landline and cell phone from August 25 to 28, about a week after the Democratic National Convention.

◾ According to Real Clear Politics’ polling average, Harris has maintained a slight lead over Trump since the August convention. Before President Joe Biden exited the race, Trump was around 3 points ahead of him.

Which signals are more reliable: bettors or voters?

How can one reconcile the differing messages from betting markets and voter polling?

Harry Crane, a statistics professor at Rutgers University, has analyzed election results since 2016, comparing them to predictions made by polling and betting markets. He notes, “The market price at any given moment reflects the collective perspective of the market based on the available information.”

The available information concerning Trump and Harris has been somewhat limited, apart from their campaigns’ exchanges. Bettors might be looking forward to September 10, when Harris is set to participate in the first presidential debate, as a key moment to reassess their bets.

It’s not just gamblers interested in the upcoming debate; a recent survey from Prolific, a digital research platform, revealed that 70% of their respondents plan to tune in. Among them, younger and Black voters showcased the highest enthusiasm to watch, according to the poll.

The evolution of betting odds for Trump’s presidential prospects

Betting odds indicating Trump’s chances of winning this year peaked on the day the Republican National Convention commenced, according to data from Betfair and Polymarket. Recently, bettors have favored him slightly over Harris for the first time after Labor Day in this election cycle.

Historically, betting favorites have lost only twice since 1866, as mentioned by the Conversation, a nonprofit news organization. One significant upset was Trump’s own loss in 2016, when bettors only assigned him a 17% chance of beating Hillary Clinton on Election Day based on historical data from Betfair.

How the odds for Trump and Harris have shifted for the 2024 presidential election

Betting odds are likely to change over the next two months leading up to the Election Day on November 5, especially since Betfair has already recorded $78 million in bets. However, this is only a fraction of the record-setting $2.23 billion wagered during the 2020 elections.

What has contributed to widening the odds gap between Harris and Trump recently?

For five of the past 19 days, the difference between Trump and Harris was two points or fewer; however, the gap has slightly increased over the last three days on Polymarket.

While bettors may understand Harris’s slim national advantage, they also seem to focus on reports like those from Nate Silver’s Silver Bulletin, which estimates Trump has a 56% chance of securing the Electoral College vote.