Arbitrage Sizer

Bankroll Dollars available for the modeled trade. Max contracts Optional cap before bankroll sizing. Fee or buffer Cents per leg. Use your own fee estimate. Contract sizing Whole contracts Turn off for fractional Polymarket-style sizing.

Kalshi

Cents

Bid Ask YES NO

Prices accept either cents like 47 or decimals like 0.47.

Polymarket

Cents

Bid Ask YES NO

Bid/ask spread opportunities assume both legs fill immediately.

Calculation Breakdown

No-short hedge

Buy YES + Buy NO

A matched pair pays $1 in either outcome when both markets resolve the same way. Edge per contract is 100c - YES ask - NO ask - fees.

Buy Low + Sell High

A same-side spread uses high bid - low ask - fees. It only behaves like locked arbitrage if the sell, short, or inventory leg is actually available.

Math only. Confirm the contracts have the same resolution criteria, settlement timing, liquidity, fees, withdrawal costs, and rules before treating a spread as risk-free.

Opportunity Checks

0 positive

Trade	Type	Edge	Size	Modeled Profit