US Regulator Forces Prediction Markets to Drop American Odds Format
A CFTC mandate pushed ProphetX, Novig and Kalshi to swap familiar plus/minus odds for percentages, sparking trader backlash south of the border.
This article was produced with AI assistance and edited by the ON360 newsroom.
The U.S. Commodity Futures Trading Commission has ordered federally regulated prediction exchanges to stop displaying American-style odds, a change that took effect this week and triggered a wave of complaints from traders on platforms including ProphetX, Novig and Kalshi.
ProphetX confirmed the switch in a Discord message to subscribers, following an earlier email sent Sunday. As of Monday, the app began showing percentages rather than plus-and-minus figures under spreads, moneylines, totals and props, according to Gambling Insider.
Why the CFTC intervened
The directive traces back to an Aug. 7 memorandum from the CFTC. Regulators said the traditional American odds format, long used by casino-style sportsbooks, risks misleading traders into believing they are placing a sports bet rather than trading a contract on an exchange.
Commission staff wrote that the format is “likely to mislead market participants about the nature of the transaction” and may hide information about market depth and pricing impact that percentage-based pricing makes clearer.
ProphetX told users it takes the change seriously but has no choice. “Operating in strict accordance with CFTC guidance is what allows ProphetX to remain a legally regulated exchange, available nationwide,” the company said, according to Gambling Insider.
Traders push back
Reaction on social media was swift. “Give me American odds back,” one ProphetX trader posted on Discord. Another asked whether any browser extension could convert the new percentages into familiar plus-minus figures.
Novig, a sports-focused exchange that launched roughly a month earlier, made the same switch ahead of Monday’s deadline. One trader there called the move “a huge L,” and the company responded by posting a link to its odds calculator in its Discord channel.
DraftKings and FanDuel’s prediction-market products underwent similar changes, and Kalshi users received an in-app notice when they logged on Monday, Gambling Insider reported. Not every trader objected, but the volume of complaints was enough to dominate online discussion of the shift.
Bigger fight still unresolved
The odds-format mandate lands amid broader legal battles over whether sports-linked prediction contracts should be treated as federally regulated derivatives or as gambling products subject to state oversight. Those disputes are playing out in multiple states and could eventually reach the U.S. Supreme Court.
For now, the underlying contracts remain unchanged. Only the way prices are displayed has shifted, from familiar plus-and-minus numbers to percentages that regulators argue better reflect the nature of an exchange trade rather than a sportsbook wager.
In Canada, the products at the centre of this dispute are not available to bettors. Provincial and federal regulators have kept sports and entertainment betting out of prediction markets entirely, leaving Ontario’s regulated sportsbooks and betting apps as the only legal option for wagering on games.
Players in Ontario using licensed operators still have access to standard responsible-gambling tools, including deposit limits and self-exclusion programs, regardless of how odds are formatted elsewhere.
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