Understanding Position Sizing for Kalshi Contracts

Quick rundown on position sizing, especially relevant for Kalshi's binary outcomes. Unlike stock trading where a $SAP price swing matters directly to your P&L, Kalshi contracts are about probability and payoff. Your bet is essentially a Yes/No on an event, with a defined payout. The mistake often made is treating it like a stock position where you just pick an arbitrary dollar amount. Instead, think in terms of your overall trading capital and the risk of ruin.

For example, if you're looking at a contract on $MGC, and you believe it's 70% likely to settle Yes, but the market price is 60 cents, that's positive expected value. However, going all-in, or even committing 10% of your capital, on any single contract, no matter how good the edge, is poor risk management. A commonly cited rule of thumb, especially for binary outcomes, is risking no more than 1-2% of your total capital on any single trade. If you have $1000, that's $10-20 per contract. This protects against the inevitable losing streaks that even the best models or predictions will encounter. It ensures you stay in the game, allowing your positive expected value trades to compound over time rather than being wiped out by a few bad calls.