The soon-to-be-out-of-office Republican is third favorite among the dozens of betting markets surveyed by the Oddschecker website.
Biden is in second place, in part because many believe his age makes him unlikely to stand again. He will be 82 in 2024.
Trump is now priced at 7-1 (an implied chance of 12.5 percent, according to Oddschecker) to win in 2024, having been 12-1 (7.69 percent) this time last month.
Harris is favorite at 4-1 (20 percent) and Biden is at 9-2 (18.18 percent).
CNN reported on Wednesday that a Trump campaign email had been sent to supporters to gauge backing for a 2024 run.
“He’s always been able to count on the American People for advice, which is why he asked us to reach out with ONE very important question,” states the email, which links to a “Yes” or “No” poll.
Six weeks after the election, Trump still refuses to concede. But at the start of December, he hinted that he had not given up on a seeking a second term.
“It’s been an amazing four years,” Trump told a crowd at the White House. “We’re trying to do another four years. Otherwise, I’ll see you in four years.”
NBC News has also reported rumours of a plan by Trump to launch his 2024 campaign on the day of Biden’s inauguration next month.
The network quoted three people familiar with the discussions as saying that “preliminary planning” was underway for an event on January 20.
Trump was also rumored to have been planning a 2024 campaign launch immediately after the Electoral College cast their votes on Monday.
But that passed without any official announcement from the outgoing president.
Trump has already raised millions of dollars for his leadership political action committee, Save America.
However, it would be unprecedented in recent history for a defeated president to run for another term. The last to do so was Grover Cleveland, who won the 1892 election after losing office in 1888. He is the only president in history to serve two non-consecutive terms.