Ben Shelton outlasted Carlos Alcaraz across five sets Tuesday night in New York, and the American sits two wins from a US Open title. Prediction market traders reacted within minutes, and Ben Shelton odds now rank second in the field behind Alexander Zverev.
Two promos cover the semifinal round. Kalshi promo code ACTION pays a $25 bonus after a $25 trade. Polymarket promo code ACTION turns a $10 deposit into a $50 trading bonus.
Ben Shelton Odds on Kalshi
| Player | Price |
|---|---|
| Alexander Zverev | 44 cents |
| Ben Shelton | 37 cents |
| Frances Tiafoe | 10 cents |
| Alexander Blockx | 4 cents |
Ben Shelton Odds on Polymarket
| Player | Price |
|---|---|
| Alexander Zverev | 45.5 cents |
| Ben Shelton | 37.2 cents |
| Frances Tiafoe | 10.4 cents |
| Alexander Blockx | 3.4 cents |
Each price reads as an implied probability. Ben Shelton odds at 37 cents mean the market gives him roughly a 37% chance to lift the trophy. A winning contract settles at $1, so 37 cents pays 63 cents of profit per share.
Two Americans, One Semifinal Spot
Shelton meets Frances Tiafoe on Friday, Sept. 11, with the start time still TBD.
That bracket guarantees an American in Sunday's final, and it explains why Ben Shelton odds and Tiafoe odds both climbed overnight. Shelton holds the ranking edge, the serve, and the momentum from beating the tournament favorite.
Volume on both apps spiked during the Alcaraz match, which matters.
Kalshi vs. Polymarket for US Open Tennis
Kalshi operates as a CFTC-regulated exchange with a clean mobile app and same-day tennis markets. Polymarket runs on similar mechanics with slightly different pricing, and the 8-tenths gap on Zverev shows why checking both apps pays off.
Traders who want the best prediction market promos claim each offer once. Together they rank among the best prediction market promos available for the closing week of the US Open.
Claim Both Prediction Market Promos
Kalshi promo code ACTION: register, enter code ACTION, trade $25, collect a $25 bonus.
Polymarket promo code ACTION: register, enter code ACTION, deposit $10, collect a $50 trading bonus.
Eligible states for both offers: 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.
New accounts take about three minutes to fund, which leaves plenty of runway before Friday. Grab the Kalshi promo code ACTION and the Polymarket promo code ACTION today, then track Ben Shelton odds through the semifinal on two of the best prediction market apps in tennis.
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.
18+ Only. Restrictions and eligibility requirements apply. Not available in all jurisdictions. Trading involves high risk and may result in loss of your entire investment. See polymarket.us/tos for more information. The Polymarket US App serves as an independent software provider and affiliate of Polymarket US and Polymarket Clearing, the CFTC-regulated derivatives exchange and clearing organization. Not available in AZ, IL, MA, MD, MI, MT, NV, OH, and WA.
