Why do Polymarket and Kalshi disagree on the Knicks' NBA title chances?

The New York Knicks won their first NBA title in 53 years in June. Less than two weeks before they raise the banner and start a new season, the prediction markets don't believe in a repeat. The two biggest exchanges can't agree on how much to doubt them.

Polymarket gives the Knicks a 13% chance of winning the 2027 championship versus 9% at Kalshi. Both markets have real depth. Polymarket's title market has traded about $23.7 million since May, and Kalshi's has traded almost $22 million.

The four-point gap is the biggest difference among the contenders, meaning that Polymarket traders rate the champions about 44% more likely to win than Kalshi traders do.

Both exchanges put last season's Western Conference finalists on top, with the Spurs at 22-23% and the Thunder at 19-22%. LeBron James' Philadelphia 76ers are next on Kalshi at 11%, with the Knicks ahead of Philadelphia on Polymarket. Kalshi also makes the Sixers slight favorites to win the East, 23% to 21%.

Are prediction markets underestimating the Knicks?

The logic behind the rankings is that San Antonio and Oklahoma City are young teams still rising, and traders are paying for that trajectory. Philadelphia spent the summer adding LeBron James and Jaylen Brown.

The counterargument is on the court. The Knicks swept Philadelphia 4-0 in last season's East semifinals before beating San Antonio 4-1 in the Finals. LeBron also turns 42 in December, so his impact is diminishing.

Predictbook's read is that Kalshi's 9% undersells the Knicks, and Polymarket's 13% is closer to fair. A team that swept Philadelphia and beat San Antonio in five shouldn't trail a roster built around a 42-year-old in their first season together.

The first test arrives on Tuesday, October 20, when the Knicks raise their championship banner at Madison Square Garden and host the new-look 76ers. One game proves little, but it's the exact kind of headline result that sows the early seeds of conviction.