Guides

Straight answers about Kalshi, Polymarket and Polymarket US, checked against each venue. Nothing here is advice.

• What does 55¢ mean on Kalshi or Polymarket?

  Checked October 17, 2026

  A prediction-market price is the market’s chance of an outcome: 55¢ is about 55%. How that maps to American odds, what you win, and what the fee does to your break-even.

• Polymarket US vs Polymarket: two exchanges, not one

  Checked October 17, 2026

  Polymarket and Polymarket US are separate exchanges with separate accounts, order books, fees and price grids. Who can use each, what each charges, and how far their prices can differ.

• Limit orders vs buying the ask on Kalshi

  Checked October 17, 2026

  Buying the ask fills now and pays the taker fee; a resting limit order waits for a seller and usually pays nothing. What resting saves, when it backfires, and what a week of real games showed.

• What happens to a Kalshi or Polymarket bet when a game is postponed?

  Checked October 17, 2026

  Each venue writes its own postponement rule into every market: how long it waits for a makeup game, and what it pays if the game never comes. Kalshi, Polymarket and Polymarket US, side by side.

• How the Screener finds the cheapest fill

  Checked October 18, 2026

  The Screener reads every venue’s order book and shows where your size fills cheapest after fees. A worked example on Senate control: 500 Yes contracts on Polymarket US for $314.74 against $323.16 on Kalshi.

• Prediction market arbitrage: Kalshi vs Polymarket vs sportsbooks

  Checked October 18, 2026

  When buying both sides on Kalshi, Polymarket US or a sportsbook locks in a profit, when the fees eat it, and four ways an arbitrage turns out not to be real.

For the numbers on a specific trade, the free tools work out fees, odds and break-even on all three exchanges. For measurements, see research.