How I built a fake market data generator for trading UIs, no API keys, zero dependencies

Every time I built a trading UI, I hit the same wall - real data feeds cost thousands per month. Free APIs have strict rate limits. And I just wanted to test my UI. So I built trade-data-generator , an npm library that generates realistic synthetic market data for equity, forex, and crypto. The Problem Building a trading UI requires live market data. Your options are: Bloomberg/Refinitiv — $2,000+/month Free APIs — rate limited, unreliable Hardcoded fake data — not realistic, The charts look bro