Market Edge

Compare the price of a YES or NO share with your own probability. See expected value, fee-adjusted break-even, payout, and a fractional-Kelly position size.

No live market data. Enter the price of the exact side you would buy.

Position

Contract side

YES NO

Market price

Cents paid per $1 winning share.

Your probability

Chance that this selected side wins.

Planned stake

Risk bankroll

Fee on winning profit

Set to 0 if fees are already in the price.

Kelly fraction

—

YES side

Payoff at your stake

If the share wins—net profit after entered fee

If the share loses—stake at risk

What the math says

EV = p × net win − (1 − p) × stake
Kelly uses the entered probability and fee-adjusted net odds. It is highly sensitive to bad probability estimates; fractional Kelly reduces, but does not remove, that risk.