Kelly criterion position sizer
Kelly stake = (b × p − q) ÷ b, where b is net odds ((1 − price) ÷ price), p your probability and q = 1 − p. Most traders bet a fraction (¼ or ½) of full Kelly.
Why fractional Kelly
Full Kelly maximises long-run growth only if your probabilities are exactly right. They never are. Overestimating your edge with full Kelly leads to deep drawdowns; half or quarter Kelly gives up a little growth for much smoother results. More in bankroll management.
Ready to try it? Check it is available where you live, then open Polymarket.
Open Polymarket