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Fees

Fees are platform charges that reduce net results and raise the break even probability.

Definition

Fees are costs charged by a platform when you trade. They reduce net outcomes and raise the break even probability needed to justify a given market price.

Why it matters

Fees can be small in isolation but large relative to typical edges in prediction markets. When price moves are bounded, even modest fees matter.

How to think about fees

• Measure edge first as probability difference: edge.

• Then adjust for costs using break even probability.

• If spreads are wide, combine fee awareness with spread metrics from effective spread.

Common pitfalls

Ignoring both sides: Some platforms charge on entry and exit.

Comparing across venues: Fee schedules differ by product and market.