By PredictQ Team // Updated: August 2026
Underdog Predict exists for one type of person: someone who already has the Underdog Fantasy app open. It lives as a tab inside the same app as pick’em and best ball, shares your account and your balance, and focuses almost entirely on sports. Live since September 2, 2025, it runs as a CFTC-registered futures commission merchant, and in March 2026 Underdog bought Aristotle Exchange (the CFTC-licensed exchange and clearinghouse behind PredictIt) to run its own rails. That migration finished in July 2026: trades now execute on Underdog’s own exchange, giving it all three major CFTC licenses.
Polymarket is the opposite animal. A standalone exchange, relaunched in the U.S. on December 2, 2025 through its acquired CFTC-licensed exchange and clearinghouse (QCEX), covering politics, sports, geopolitics, crypto, and culture, with $200 million-plus daily U.S. volume by June 2026 and some of the deepest political order books anywhere.
State coverage cuts both ways here. Underdog Predict runs in 31 states plus DC, including the big sportsbook-free prizes (California, Texas, Florida), but skips New York, New Jersey, Illinois, Pennsylvania, Ohio, and Michigan. Polymarket reaches roughly 40 states, also minus New York. Neither map is complete; check the app before you plan anything.
Quick Verdict
Polymarket, unless you’re already an Underdog regular. It has more markets, deeper liquidity, better fee structure for traders, and an actual welcome bonus (deposit $10, get $20). Underdog Predict has no dedicated Predict bonus at all; the Play $5, Get $50 offer is DFS bonus entries you can’t spend on event contracts. The DFS integration is Underdog’s entire pitch, and it’s a good pitch for exactly the people who already live there.
Side-by-Side Snapshot
Regulation: Polymarket operates its acquired CFTC-regulated exchange on an intermediated basis. Underdog Predict is a CFTC-registered FCM with trades executing on its own Aristotle-based exchange, live since July 2026, with clearing handled in-house.
Bonus: Polymarket, deposit $10 and get $20 in trading bonus. Underdog, no Predict-specific offer; the DFS deal (Play $5, Get $50 in bonus entries) applies to fantasy only.
States: Polymarket, roughly 40. Underdog Predict, 31 plus DC.
Markets: Polymarket spans politics, sports, geopolitics, crypto, culture. Underdog is sports-first with some politics, culture, and economics markets.
Fees: Polymarket publishes category taker rates (0% Geopolitics, up to $0.75 per 100 shares Sports), with makers always free. Underdog charges per-contract fees in line with other brokered platforms; check the current schedule in-app.
Structure: Polymarket is standalone. Underdog Predict shares one app, one login, one balance with Underdog Fantasy.
How to Think About the Choice
The integration argument is real but narrow. If you’re drafting best ball teams every night, Underdog Predict removes every ounce of friction: no new account, no new deposit, event contracts two taps from your pick’em slate. The moment you’re opening an app specifically to trade prediction markets, that advantage evaporates and you’re left comparing product against product.
Product against product, Polymarket wins nearly every column. Category breadth is a blowout; Underdog has no geopolitics, minimal crypto and culture coverage, and its politics selection is shallow next to books that moved billions during the 2024 cycle. On sports, where Underdog actually competes, Polymarket generally has comparable or deeper liquidity in mainstream contracts, and its maker-pays-nothing structure rewards anyone patient enough to post a limit order.
The bonus gap is the most concrete difference. Polymarket pays you $20 in trading bonus on a $10 deposit. Underdog pays Predict users nothing; its famous $50 offer converts to DFS entries, useful only if you wanted DFS anyway. For a prediction-markets-first user, one platform is handing you a bankroll and the other is handing you a coupon for a different product.
The Aristotle move shipped. As of July 2026, Underdog owns and operates its own exchange and clearinghouse, the upgrade from brokered access to vertical integration, the same structural move DraftKings made with DKeX in June 2026. There’s bigger money behind it too: IG Group agreed on July 30, 2026 to acquire Underdog for up to $1.3 billion, pending regulatory approvals. Vertical integration is now a reason to choose, not a roadmap item.
Pick Polymarket If
You want markets beyond sports: politics, geopolitics, crypto, culture.
You want the deepest political books and 0% Geopolitics fees.
You want a real welcome bonus on a real-money exchange.
You use limit orders and want maker rebates.
You don’t already have an Underdog account.
Polymarket promo: deposit $10, get $20 trading bonus →
Pick Underdog Predict If
You’re an active Underdog Fantasy player and want event contracts in the same wallet.
You’re sports-only and value one app over one more edge.
You’re in one of its 31 states plus DC (California, Texas, and Florida included) and Polymarket isn’t live for you.
You want exposure to a platform that may soon run its own exchange via the Aristotle deal.
Underdog Predict bonus code: play $5, get $50 →
Both?
For Underdog regulars, absolutely. Keep your DFS life where it is, claim Polymarket’s $20 bonus, and route your politics, geopolitics, and bigger sports positions to the deeper books. The two barely compete for the same trade. Sign up for Polymarket AND sign up for Underdog Predict.
Bottom Line
Both of these are real exchanges now. Polymarket gives you the broadest books in the business, from politics to geopolitics to crypto, with the deepest liquidity. Underdog gives you a sports-fan product running on its own CFTC exchange, with IG Group money on the way. Pick Polymarket for breadth. Pick Underdog if your trades start where your DFS lineups do. Plenty of traders should run both.
Disclosures: PredictQ may receive compensation when readers sign up for platforms through links on this page. Information accurate as of August 2026. Polymarket operates in the U.S. through its acquired CFTC-regulated exchange and clearinghouse (QCEX) on an intermediated basis; availability varies by state. Underdog Predict is operated by Underdog as a CFTC-registered Futures Commission Merchant, with trades executing on Underdog’s own CFTC-regulated exchange and clearinghouse. Trading event contracts involves significant risk. This content is for informational purposes only. Must be 18 or older. If you or someone you know has a gambling problem, call 1-800-GAMBLER.