Exchange Fees
What a bet really nets at every prediction market and betting exchange: the trading fee as a maker or a taker, commission on winnings, and what it costs to get money in and out.
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Held to settlement, whole contracts only. Break-even is the win chance the bet needs after every fee. A maker's resting order only pays maker fees if someone fills it.
Fee schedules
Costs that are easy to forget
The spread
A taker pays the ask, not the middle. On a 48¢ / 52¢ book, buying at 52¢ costs 2¢ a contract before any fee, often more than the fee itself.
Selling early pays twice
Per-contract fees (Kalshi, Polymarket, the brokers) are charged again when you sell before settlement. Commission on winnings (ProphetX, Betfair) isn't.
Rounding up
Kalshi rounds each order's fee up to the cent. One 100-contract order pays far less than a hundred 1-contract orders.
Deposit fees
Debit cards and Apple Pay cost 2–4% at several apps. On a $100 bet at 50¢, a 3% card fee wipes out 3% of the $100 you could win.
Withdrawal fees and minimums
PredictIt keeps 5% of every withdrawal, instant cash-outs cost 1.5–1.75%, IBKR charges after the first free one each month, and Novig's minimum is $10.
Makers don't always fill
A resting order saves the fee (or earns a rebate) but can sit unfilled, or fill only when the price is moving against you.
Interest on your money
Some exchanges and brokers pay interest on cash or open positions (IBKR pays a coupon of about 3–4% a year), which offsets fees on long-dated futures.
Taxes
Exchange winnings are taxable. Brokers may send a 1099, and how losses offset gains depends on the platform's tax treatment, so keep your own records.
Bonus playthrough
Sign-up credits often must be traded before you can withdraw them; count that playthrough as cost. See the Bonus Finder.
Fees change often, and some of these come from reviews rather than each exchange's own published schedule (marked "Reported"). Check the exchange's fee page and the order confirmation before you trade. Not financial advice. Predict2Win is for adults 21 and older, and each exchange has its own age and state rules.