Claude Builds a Market Timing Web Game

noir_chat · reddit · 2026-07-15

Using Claude, the author created the web game **beatthecouch.com**. Players attempt to beat a "buy and hold" couch using buy/sell buttons across an unknown two-year historical market window to test if market timing can beat long-term holding. Key project designs include: - Running **1,000 permutation tests** per win; if it fails to beat the 90th percentile of random monkeys, it's flagged as "LUCKY". - The game is a ~**300KB single-file HTML** with no frameworks, tracking, or accounts. - Idle cash earns interest based on historical **3-month Treasury bill rates**. - Global and daily leaderboards rely solely on a lightweight **Cloudflare Worker + D1**. The author notes limitations: it only supports US indices, data ends in 2019, and the dataset/windows are visible in the source code, making cheating theoretically possible. Currently, the "couch" still leads the global leaderboard, and even the author hasn't beaten it.

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