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Seattle Mariners vs. Colorado Rockies odds, Sep 19: Kalshi vs Polymarket

Seattle Mariners 54% on Kalshi, 53% on Polymarket. Both exchanges' prices for every outcome of Seattle Mariners vs. Colorado Rockies, Sep 19, $1 traded in 24 hours, updated every 45 seconds.

Sat, Sep 19, 2026, 8:10 PM ET · MLB games · $1 traded in 24h across both venues

Seattle Mariners: Kalshi $0.54 vs Polymarket $0.53, +$0.01

Mid prices, in dollars on a contract that pays $1 if it happens: $0.54 is a 54% chance. The gap is Kalshi minus Polymarket.

Two separate exchanges, two accounts. Links may carry a referral code, which never changes what is shown. Disclosures.

-8.24% after fees
Buy Seattle Mariners @ Polymarket $0.55, Colorado Rockies @ Kalshi $0.50

All outcomes

OutcomeKalshi bid / askPolymarket bid / askGap, + = Kalshi higher
Seattle Mariners$0.52 / $0.57$0.51 / $0.55+$0.01
Colorado Rockies$0.42 / $0.50$0.45 / $0.49−$0.01

Price history, last 3 days

6 snapshots · teal Kalshi · violet Polymarket

How this is matched

Games are matched across the two exchanges by league, team codes and date. Polymarket prices come from its live order book, Kalshi from its public API. Refreshed every 45 seconds.

What this is not

Read-only. Nothing here places or routes orders and nothing is advice. Fees, slippage and the time it takes to move money between venues are not in these numbers.

More

All MLB games disagreements · Full price history · Daily reports