Kalshi EVX - Market Metrics

Real-time EV Calculator, Kelly Bet sizing, and Market Vig tracking for Kalshi markets.

Kalshi EVX – Market Metrics is a browser extension that adds an analytical overlay to Kalshi prediction market pages. It integrates directly into the existing Kalshi interface and displays real-time, math-based metrics derived from market prices to help users better understand probabilities, pricing, and risk. Price alone does not always reflect probability. This extension highlights how market prices relate to user-defined assumptions and market structure, allowing for clearer interpretation of market data. What the Extension Does The extension performs three core analytical calculations in real time: 1. Expected Value (EV) Metrics Using a simple belief slider (for example, “I estimate a 20% probability”), the extension evaluates how market prices compare to that assumption and displays the resulting expected value metrics directly on each contract. - Green badges indicate positive expected value under the selected assumption - Neutral or muted badges indicate unfavorable or neutral value These indicators update instantly as inputs change. 2. Kelly-Based Position Sizing (Informational) Based on the selected probability and user-entered bankroll value, the extension displays a mathematically derived reference size using a conservative Kelly-style calculation. This metric is shown for informational purposes only and is designed to illustrate relative risk exposure under different assumptions. 3. Market Vig (Spread) Indicator The extension calculates the implied market spread (“vig”) using displayed prices. This helps users identify how pricing efficiency varies across markets and highlights when spreads are relatively wide or narrow. Key Benefits Automatically computes probabilities, expected value, and pricing relationships without external tools. Surfaces markets where price relationships differ significantly from selected assumptions. Color-coded indicators are displayed directly within the Kalshi interface for rapid comparison. All calculations run locally in the browser. No user data is collected, stored, or transmitted. Key Features - Interactive probability (belief) slider - Support for mutually exclusive and cumulative market structures - Toggle between raw value and percentage-based metrics - Lightweight, local-only execution - No account access and no order interaction