15-Minute Crypto Up/Down Arbitrage with Hedged Spread Making

How It Works Three repositories (kenfri13/polymarket-arbitrage-trading-bot, Corettafinnougricspeaking368/Polymarket-Arbitrage-Trading-Bot-Spreadmaker, and Juanp2389/Kalshi-trade-bot) describe variants of the same core strategy applied to 15-minute crypto markets. The bot simultaneously quotes or takes both the Yes and No sides of a binary outcome market when the combined cost of both sides is less than $1 (i.e., the book is inefficient), capturing the difference as profit at resolution. The Corettafinnougricspeaking368 variant explicitly frames this as a spread-making strategy with a configurable entry cost ceiling.

Entry / Exit Conditions Entry fires when Yes_price + No_price < 1.00 minus fees, guaranteeing a positive expected value regardless of resolution. The Kalshi variant also monitors the same BTC 15m contract on Kalshi, entering when a price gap exists between the two platforms and pairing trades cross-platform. Exit is at market resolution; early exit is possible if the spread collapses before resolution.

Verification The kenfri13 repo was created in 2025 and has been actively updated through June 2026, suggesting sustained development. No explicit P&L figures are disclosed.

Implementation Notes The Gamma API is used for market discovery and pricing. Configurable hedge thresholds and risk management modules are mentioned. The Kalshi cross-platform variant requires API access to both Kalshi and Polymarket simultaneously, with careful attention to settlement timing differences.

Risks Both sides of the book may not fill simultaneously, creating directional exposure. Fees can erode the spread. Liquidity on 15-minute markets is often thin, limiting position size. Cross-platform variant adds counterparty and regulatory risk on Kalshi side.