MLB Prediction Market Apps: Top Sign-Up Bonus Offers on August 8

From early afternoon action at Fenway Park to prime-time divisional clashes on FOX, new traders can explore the best MLB prediction market apps, with access to trading bonuses to load up ahead of MLB’s Saturday slate

Four nationally televised matchups, across FS1 and FOX, give prediction market fans the ability to trade moneylines, run lines, and totals, all with prediction market promos, bonuses, and credits in their back pocket.

Want to take a look at the top MLB prediction market apps worth pinning to your phone for Saturday's slate? Check out our expert breakdown below.

MLB Prediction Market Promos for Saturday

Saturday, August 8, 2026 MLB Game Facts

With four games on national television this Saturday, there is something for everyone to check out. From major AL clashes with postseason berths on the line, America’s pastime is set to offer some primetime entertainment.

1. Athletics vs. Red Sox (4:10 p.m. ET | FS1 | Fenway Park)
2. Orioles vs. Rangers (7:15 p.m. ET | FOX | Globe Life Field)
3. Guardians vs. White Sox (7:15 p.m. ET | FOX | Guaranteed Rate Field)
4. Tigers vs. Giants (7:15 p.m. ET | FOX | Oracle Park)

What Are the Best MLB Prediction Market Apps?

Prediction markets operate under CFTC oversight, replacing traditional sportsbooks with peer-to-peer exchanges. Instead of betting against the house, traders buy and sell contracts against each other.

These platforms cover all standard baseball angles—including moneyline winners, run lines, team totals, player pitch counts, and postseason futures. Welcome bonuses make it even easier for you to get involved. Perfect for new players looking to try their hand without risking too much of their hard-earned cash.

1. Polymarket Mobile App

Polymarket stands out as a high-value predictions market app with a great guaranteed bonus. Entering the Polymarket promo code ACTION and completing a single $10 deposit instantly unlocks a $20 trading bonus—requiring no qualifying trades to trigger the credit.

An official data partnership with MLB Sportradar makes managing positions with Polymarket easy, especially during Saturday night’s FOX triple-header (Orioles vs. Rangers, Guardians vs. White Sox, Tigers vs. Giants). When bullpen switches occur or momentum shifts at Globe Life Field, Polymarket’s instant adjustments allow you to lock in profit before traditional books reprice.

2. FanDuel Predicts App

FanDuel Predicts adapts traditional sportsbook design for CFTC-regulated prediction markets. Perfect for anyone looking for a seamless transition into prediction market apps alongside a handy sign-up bonus.

The platform's early cash-out feature is especially useful for managing your late-game risk: if a starting pitcher gets pulled early or a late-inning rally threatens a run-line position on MLB Saturday, you can exit positions early to lock in gains or limit losses.

3. Kalshi Mobile App

As the longest-tenured CFTC-regulated market in the United States, Kalshi offers the deepest baseball prop menu in the prediction industry. And $25 in trades across early prop markets unlocks a randomized bonus credit up to $500, able to be used across the remaining night games, from the Kalshi promo code ACTION.

These in-depth MLB markets on their app are ideally suited for Saturday's slate. Traders can buy contracts on elevated run totals at hitter-friendly Fenway Park while simultaneously taking low-scoring pitcher props at marine-layer-heavy Oracle Park, opening up a world of possibilities for traders. More options equals more opportunity.

4. Novig App

Novig operates as a zero-commission peer-to-peer exchange app, designed to eliminate the house edge. By matching trades directly against other players, Novig routinely offers sharper prices than standard online sportsbooks with no-vig taken from its players.

Eliminating sportsbooks' margins allows you to maximize your trading on Saturday's MLB national broadcasts, especially after signing up with the Novig promo code ACTION, spending $25 and getting $50 in Novig Coins. This enables you to explore Saturday's full MLB slate, with bonuses and the house taking nothing from you.

5. DraftKings Predictions App

DraftKings Predictions brings the familiar DraftKings experience to the growing prediction market space, giving traders a straightforward way to take positions on sports outcomes and other events. The platform also offers a strong new-user incentive, with a small initial trade unlocking $150 in Predictions Dollars.

For Saturday's MLB slate, DraftKings Predictions gives sports fans another way to trade alongside the day's nationally televised games. Whether you're looking to take a position before first pitch or react to an injury, pitching change, or late-game swing, the app provides another option for managing predictions throughout the day's action.

6. ProphetX Prediction Market App

ProphetX provides a dedicated, sports-focused exchange environment free from political or economic market clutter. Placing a simple $10 opening trade after using the ProphetX promo code TANBONUS on the afternoon Athletics vs. Red Sox broadcast delivers $20 in bonuses, giving you some extra cash to trade on the prime-time FOX games.

Tailored specifically for sports traders, ProphetX is perfect for the massive set of MLB games we have coming our way on Saturday. With four nationally televised matchups and 15 matchups across the whole day, from 3:05 pm ET to 9:50 pm ET. You need look no further if you’re purely focused on making the most of this Saturday’s MLB matchups.