LeBron James signs with Polymarket after DraftKings deal expires

LeBron James has signed what Polymarket describes as an exclusive partnership, the first individual deal between an NBA player and the prediction market platform. James announced it in a 14-second video posted to X on 5 September.

The video shows him leaving a lift at what the caption calls Polymarket HQ, with floor buttons for sports, politics, crypto, economy, culture, weather, esports and technology. It drew close to 10 million views in seven hours, according to Front Office Sports.

A Polymarket spokesperson told The Athletic that more details would follow on Tuesday 8 September. “With football season around the corner, we look forward to tapping into James’ love for the sport and exploring other ways to bring Polymarket to wider audiences,” the spokesperson said.

Terms, duration and any equity component have not been disclosed.

James moves across from DraftKings

James endorsed DraftKings from 2024 until that agreement expired in the summer of 2026, according to Front Office Sports. The same slot in his endorsement roster now goes to a platform regulated federally by the Commodity Futures Trading Commission (CFTC), not a sportsbook licensed state by state.

The NBA has no blanket prohibition on players endorsing prediction markets, on the same basis it applies to sports betting, though players cannot promote NBA-specific event contracts. One active Polymarket market covers whether James will play alongside his son Bronny during the 2026-27 season. James, a four-time champion and four-time MVP, is now with the Philadelphia 76ers.

Kalshi signed three athletes first

Kalshi signed three athlete deals earlier in 2026. Golfer Bryson DeChambeau signed in January. Giannis Antetokounmpo followed in February and became the first NBA player to invest in the company. In June, Kalshi signed the Argentina national football team, with Lionel Messi.

Polymarket’s sports promotion has run through leagues, teams and one tennis player. Maria Sharapova has demonstrated trading on the platform through social media. Front Office Sports reports Polymarket agreements with MLB, the NHL, MLS and European football competitions, plus team deals with the New York Yankees and the New York Rangers.

Polymarket is raising at a $21bn valuation

Polymarket is raising about $1 billion at a $21 billion valuation, reported on 1 September, up 40% from the $15 billion mark set earlier in 2026. 1789 Capital is leading the round with $300 million on top of an existing $200 million position.

Intercontinental Exchange (ICE), which owns the New York Stock Exchange, remains the largest shareholder at around 22%. ICE has committed up to $2 billion since October 2025, when it first invested at a valuation of roughly $8 billion, and added $600 million in March 2026. ICE recorded a $389 million fair-value gain on the position in the first quarter of 2026.

The legal question is still open in the US

The endorsement lands while the status of sports event contracts is being decided in court. On 1 September the Ninth Circuit ruled 3-0 that Nevada can regulate Kalshi’s sports event contracts under state gaming law, splitting with the Third Circuit’s April decision. Nevada obtained a preliminary injunction against Polymarket in June.

Polymarket also said on 1 September that its trade surveillance was ready for the 3 November US midterms, with more than 100 cases referred to law enforcement.

Outside the US, Spain’s Directorate General for the Regulation of Gambling (DGOJ) ordered the blocking of both Polymarket and Kalshi in May, and South Korea ordered domestic internet service providers to block Polymarket in August.

Polymarket said the campaign detail comes on Tuesday. What it puts James’s name to, and in which states, is the part operators and regulators will read closely.

Source: The Athletic, Front Office Sports, Yogonet