Underdog, the fantasy-sports app, acquired a CFTC-registered exchange and clearinghouse in March 2026 and launched Underdog Predict inside its existing app. You trade yes/no contracts on sports, politics, economics, entertainment and weather for a flat 2¢ per contract, in roughly 36 states. It's a real exchange product with fantasy-app marketing: deposit matches that need $2,000 to max out and can't be spent on straight picks. Fine for Underdog users; not a destination for anyone else.
How it's built
Rather than route to Kalshi like Robinhood, Underdog bought the infrastructure: a Designated Contract Market and a clearinghouse, acquired in March 2026. That puts it in the small group (Kalshi, Polymarket US, Novig, ProphetX, Gemini) that controls its own order book and rules. The product launched into the same app as Underdog Fantasy, so existing users see it next to their pick'em entries.
Markets
Sports lead: NFL and college spreads, totals, moneylines and parlays. Beyond sports there are politics, economics, entertainment and weather contracts, broader than the sportsbook-owned apps but shallower than Kalshi. Underdog also runs contests on top, such as the "Keep Your Million" promotion that started August 28, 2026.
Fees
2¢ per contract at purchase, regardless of price. That's 4% of a 50¢ contract and 10% of a 20¢ one, so it's priced for favourites and parlays rather than cheap longshots. No separate maker pricing is advertised.
Promotions, and the catch
The headline is a deposit match up to $1,000, which requires a $2,000 deposit, with a $10 minimum to get anything. Bonus funds generally cannot be used on straight Prediction Picks, which steers them toward combo products with worse odds. If you're depositing for the match, read what the bonus can and can't touch first.
Availability
About 36 states plus DC, varying by product and by state action. Underdog lists eligible states in-app.
Who it's for
Underdog Fantasy users who want to trade events without leaving the app. For everyone else, Kalshi has lower fees on most prices, more markets and more states; Novig and ProphetX are cheaper for sports singles.
Structure, fee and promotion details per SI (Oct 11, 2026) and Legal Sports Report (Oct 14, 2026).