Others take a darker view.

After the September court ruling, the watchdog group Better Markets warned that allowing such bets would “corrupt the integrity of our elections, trigger market manipulation, and victimise countless investors”.

Prof Gruca said he thought elections bets were a “sideshow” when it came to threats to democracy.

But debate over the issue is likely to continue.

In the US, states regulate betting and some have banned election bets outright.

Prediction markets – which differ from gambling because they rely on trading rather than a centralised company overseeing the odds – fall under the jurisdiction of federal markets regulators, who have long taken a dim view of such activity.

But betting norms have been loosening in the US, notably after the 2018 Supreme Court ruling that paved the way for sports gambling.

In May, responding to the uptick in applications from firms seeking to offer trading on events, the Commodities Futures Trading Commission (CFTC) proposed a rule that would explicitly bar trading on political contests.

“Contracts involving political events ultimately commoditise and degrade the integrity of the uniquely American experience of participating in the democratic electoral process,” CFTC chair Rostin Behnam said at the time.

He warned that allowing such trading would push the CFTC beyond its mandate and expertise, giving the role of “election cop”.

In the end, resolving the question could well be another election bet.