Prediction Market Returns Calculator

Expected value

— cents per contract, or — return, which is — annualized.

EV = p - c
return = (p - c) / c
annualized = (p - c) / c × 52 / t

Sharpe ratio

—, which is — annualized.

(compared to ~0.43 for the long-run US stock market, and ~0 for Treasuries)

S = (p - c(1 + r)t/52) / √(p(1 - p))
annualized = S × √(52 / t)

Kelly fraction

— of your bankroll.

f* = (p - c(1 + r)t/52) / (1 - c(1 + r)t/52)

Caveats