New Kalshi users can use promo code ATSBONUS to get a $25 trading bonus after transacting at least $25 within 30 days. The offer is available to eligible new customers who complete Kalshi’s account and identity-verification requirements.

Polymarket lets you trade event outcomes by buying and selling Yes or No shares. The basic idea is simple: if a share wins, it settles at $1.00. If it loses,…