The NBA is tightening control over bets that could reward manipulated performances, but its authority does not extend to every platform where fans trade on basketball outcomes.
As prediction exchanges fall outside the NBA’s agreements, this raises the question of whether they will adopt the same limits as concern over insider trading grows.
According to InGame, which cites a league letter obtained by ESPN, the restrictions include:
- Parlays combining multiple statistical unders for the same player.
- Wagers on the winner of the opening tip.
- Certain negative outcomes involving individual plays, including missed shots.
- Unders on players expected to play fewer than 12 minutes.
An under wins when a player finishes below a specified statistical threshold.
Combining several unders can allow a bettor to profit across multiple categories if that player makes an unexpectedly early exit.
DraftKings said the changes partly formalize limits it already applies.
“The NBA’s guidance formalizes many of the market restrictions already reflected in DraftKings Sportsbook’s practices,” a spokesperson told InGame.
The restrictions address a vulnerability first exposed by the Jontay Porter scandal; advance knowledge of limited playing time can affect several wagers simultaneously.
The NBA banned Porter in April 2024 after finding that he had wagered on NBA games and even limited his participation for betting-related reasons.
For example, an early departure off the court can reduce a player’s opportunities to score and assist.
A bettor who therefore knows about a planned departure beforehand could hold an advantage across those two markets.
Public pages reviewed by CCN on Oct. 19 show that both exchanges offer NBA trading.
Kalshi’s basketball hub lists individual matchups alongside spread and total markets.
Polymarket US also lists upcoming NBA games, while its separate international platform carries markets including the 2027 championship.
As CCN previously explained, sports prediction contracts have become a focal point of the dispute between federal derivatives regulation and state gambling oversight.
An exchange contract and a sportsbook wager can expose users to the same sporting outcome, yet operate under different regulatory structures.
A future agreement with a prediction exchange could give the league greater contractual influence over that operator’s products.
Legal Sports Report reported that the NBA had not announced such a partnership when the restrictions emerged.
The NBA’s restrictions arrive amid broader questions about whether prediction markets adequately protect users against insider trading and manipulation.
In May, House Oversight Committee Chairman James Comer launched an investigation into Kalshi and Polymarket, requesting information about identity checks and how the platforms detect suspicious trading.
“As online prediction platforms grow and become more mainstream, some bad actors have exploited the platforms to make thousands of dollars by placing bets based on nonpublic information,” said Chairman Comer.
“Americans deserve to know that these platforms are taking steps to prevent insider trading,” he added.
Concerns have already led to concrete disciplinary action.
In February, the Commodity Futures Trading Commission issued an advisory following two Kalshi cases involving misuse of nonpublic information and fraud.
“In May 2025, social media posts contained videos that appeared to show a political candidate trading on his own candidacy on Kalshi,” the CFTC wrote in its report.
Meanwhile, in August and September 2025, “an individual traded a prediction market related to a YouTube channel while having an employment relationship… with the subject of the contract.”
Critics have also challenged whether sports contracts allow operators to bypass protections required of state-licensed gambling businesses.
As CCN previously reported, state regulators and tribal groups have contested the industry’s reliance on federal derivatives oversight, arguing that sports contracts amount to gambling subject to additional restrictions.