Risk Management for Event Contracts

# Risk Management for Event Contracts The most common reason prediction market traders lose money is not bad analysis -- it is bad risk management. You can be right 60% of the time and still go broke if you size your bets poorly. This guide covers the practical frameworks that keep your capital intact. ## The Fundamental Rule: Maximum Loss Is Your Cost Basis Unlike margin trading in stocks or futures, your maximum loss on a Kalshi contract is exactly what you paid. Buy 100 contracts at $0.40 each? Your max loss is $40. This built-in risk cap is one of the most attractive features of event contracts. But "capped loss" does not mean "small loss." If you put your entire account into one trade at $0.40, you can still lose 40% of everything on a single event. Position sizing is how you prevent that. ## Position Sizing: The Kelly Criterion The Kelly Criterion is the gold standard for bet sizing. It tells you what fraction of your bankroll to risk on a single trade: **Kelly % = (Edge / Odds)** Or more precisely: **Kelly % = (p * (b + 1) - 1) / b** Where p is your estimated probability and b is the decimal odds minus 1. Example: Market price is $0.40 (implying 40% probability). You estimate the true probability at 55%. - b = ($1.00 / $0.40) - 1 = 1.5 - Kelly = (0.55 * 2.5 - 1) / 1.5 = 0.375 / 1.5 = 0.25 Kelly says bet 25% of your bankroll. But most practitioners use **fractional Kelly** -- typically half or quarter Kelly -- because overestimating your edge is the most common mistake in trading. At quarter Kelly, you would bet about 6% of your bankroll on this trade. That is a reasonable max position size. ## The 5% Rule A simpler framework: never risk more than 5% of your total bankroll on any single market. This means: - $1,000 bankroll: max $50 per trade - $5,000 bankroll: max $250 per trade - $10,000 bankroll: max $500 per trade This rule keeps you in the game even during a losing streak. At 5% per trade, you would need 14 consecutive losses to lose half your bankroll -- unlikely if you are making positive EV bets. ## Diversification Across Categories Correlation risk is real. If you have five political trades, they might all go wrong together (e.g., a polling miss that affects multiple races). Spread your positions across: - **Different categories**: Mix politics, economics, sports, and tech - **Different time horizons**: Combine short-term trades (resolving this week) with longer-term positions - **Different probability ranges**: Do not only trade favorites ($0.70+) or only underdogs ($0.30-) A well-diversified prediction market portfolio might hold 10-20 positions across 4-5 categories with varying resolution dates. ## When to Cut Losses Event contracts have built-in resolution dates, so you always have the option to hold until settlement. But sometimes selling early is the right call: 1. **Your thesis was wrong.** New information has emerged that invalidates your original analysis. Do not hold out of stubbornness. 2. **Opportunity cost.** Your capital is locked in a position with minimal remaining edge. Selling frees it up for better trades. 3. **Risk concentration.** A position that was 3% of your bankroll has grown (or your bankroll has shrunk) and is now 10%. Trim to maintain balance. There is no shame in taking a loss. The goal is to maximize your long-term returns, not to be right on every individual trade. ## Tracking Your Performance Keep a simple trading log: - Market ticker and question - Entry price and date - Position size (contracts and dollar amount) - Your estimated probability at entry - Exit price/settlement and date - Profit or loss Over time, this log reveals your actual edge across different categories and probability ranges. You might discover you are excellent at pricing political events but consistently overpay for sports markets. This data lets you allocate capital to where your edge is strongest. ## The Bankroll Management Ladder As your bankroll grows, scale your risk proportionally: | Bankroll | Max per trade (5%) | Recommended positions | |----------|--------------------|-----------------------| | $500 | $25 | 5-8 | | $2,000 | $100 | 8-12 | | $5,000 | $250 | 10-15 | | $20,000 | $1,000 | 15-25 | ## The Psychology of Risk The hardest part of risk management is emotional. After a big win, the temptation to oversize your next bet is strong. After a losing streak, the urge to go big to "make it back" is even stronger. Both impulses are destructive. Mechanical rules -- fixed position sizes, diversification targets, stop-loss thresholds -- remove emotion from the equation. Set your rules when you are calm and follow them when you are not. The traders who survive long enough to benefit from their edge are the ones who never bet the farm on a single outcome, no matter how confident they feel.