New traders who sign up with Kalshi promo codeACTION trade $25 and collect a $25 bonus, and Monday night's nationally televised MLB game gives you an immediate spot to use it today.
The Monday, August 31 MLB slate runs throughout the evening, but the featured matchup for this offer comes from Washington: Marlins vs. Nationals at 6:45 p.m. ET on FS1 from Nationals Park. Miami enters at 69-68, while Washington sits at 65-74 heading into the final game of the series.
Kalshi Promo Code ACTION Offer Details
| Promo Code | ACTION |
|---|---|
| Offer | Trade $25, get $25 bonus |
| Available States | AK, AL, AR, CA, CO, CT, DC, DE, FL, GA, HI, IA, ID, IN, KS, KY, LA, ME, MN, MO, MS, NC, ND, NE, NH, NJ, NM, NY, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, VT, WI, WV, WY |
| Markets | MLB, tennis, and more |
How to Claim the Kalshi Promo Code ACTION Bonus
- Tap any link on this page to open the Kalshi registration page.
- Enter your name, email, and address to create your account.
- Apply the Kalshi promo code ACTION during sign-up.
- Deposit funds and trade at least $25 in qualifying volume on any eligible market.
- Collect your $25 bonus and use it on Monday's MLB games or another available contract.
The low qualifying volume makes this one of the more approachable welcome offers across the best prediction market apps, with a dollar-for-dollar bonus once you complete $25 in trades.
Marlins vs. Nationals Odds
Miami closes out its four-game set at Nationals Park still hanging around the National League Wild Card picture. Washington took the opening two games of the series before the Marlins answered Sunday with a 6-2 victory powered by a six-run ninth inning.
Here are the latest markets you can trade on for Marlins vs. Nationals with the Kalshi promo code ACTION:
| Outcome | Kalshi Contract Price | Implied Probability |
|---|---|---|
| Marlins to win | 52¢ | 52% |
| Nationals to win | 48¢ | 48% |
Kalshi currently gives Miami a 52% chance to win and Washington 48%, making this nearly a coin-flip market despite the Marlins entering with the better record.
Marlins vs. Nationals Prediction
Gusto does not give the Marlins an overwhelming advantage on the mound, but Miami is the slightly stronger club overall and enters Monday at 69-68 compared with Washington's 65-74 mark. The Marlins have also won eight of the first 11 head-to-head meetings between these teams this season despite dropping the first two games of the current series. Sign up now, and trade on my prediction with
- Marlins vs. Nationals prediction: Marlins to win (52%)
The 52-cent price is what makes the trade attractive. Miami is being asked to win only slightly more than half the time, and the broader sportsbook market is already pricing the Marlins as a modest favorite.
Sunday's comeback also reinforced one of Miami's advantages entering the finale. Washington carried a 2-0 lead into the ninth before the Marlins scored six times, turning what had been a quiet offensive game into a 6-2 victory.
There is still risk. Dion has pitched well enough to keep Washington competitive, and a 48-cent Nationals contract shows that traders see little separation between the teams tonight. But at the current number, I would rather pay 52 cents for Miami than take Washington simply because it offers the cheaper contract.
US Open First Round Continues Monday
Baseball anchors the evening, but the US Open gives Kalshi traders another full board to explore throughout Monday.
First-round action continues in New York, with defending champions Carlos Alcaraz and Aryna Sabalenka among the biggest names playing. Sabalenka faces Camila Osorio during the Arthur Ashe Stadium day session, followed by Alcaraz against Roman Safiullin. Ben Shelton and Naomi Osaka headline the evening session beginning at 7 p.m. ET.
Other Monday matches include Stefanos Tsitsipas against Arthur Fils, Iga Swiatek against Xiyu Wang and Frances Tiafoe against Martin Damm. That gives traders tennis markets before, during and after the 6:45 p.m. ET Marlins-Nationals first pitch.
Outright tournament contracts also give you a longer-term alternative to single-game baseball. Those prices can move significantly during the opening rounds as favorites advance or get knocked out, so keep an eye on prediction market promos throughout the tournament.
Why Trade MLB on Prediction Markets
Prediction markets price outcomes as yes-or-no contracts, so you can see the market's implied probability directly.
Miami trading at 52 cents, for example, means the market currently gives the Marlins roughly a 52% chance of winning tonight. If Miami jumps out to an early lead and the contract price rises, you can potentially sell the position before the final out instead of waiting for the game to settle.
That flexibility is one of the main differences between trading an event contract and placing a conventional sportsbook wager.
Kalshi also offers multiple ways to trade the same baseball game, including game-winner and first-inning markets. Traders who follow our Kalshi predictions can compare those prices before entering a position.
Sign up with Kalshi promo code ACTION, trade $25, and collect your $25 bonus in time for Monday's MLB slate. Kalshi promo code ACTION applies at registration only, so enter it when creating your new account.
Certain limitations apply. The offer is available to new users only, subject to the terms and conditions. 18+ only. Restrictions and eligibility requirements apply. Event contract trading involves significant risk and is not appropriate for everyone. Please carefully consider if it is appropriate for you in light of your personal financial circumstances. Kalshi products are not available in all jurisdictions. See kalshi.com/regulatory for more information. Not available in AZ, IL, MA, MD, MI, MT, NV, OH, and WA.
