Jane Street did $16.1 billion in trading revenue in Q1. JPMorgan did $11.6 billion. Goldman did $9.34 billion. Morgan Stanley did $8.51 billion. Jane Street has roughly 3,500 employees. The three banks above have firm-wide headcounts of 318,000, 48,000, and 80,000. Most of those people don't trade. They run branches, process credit cards, do wealth management, run M&A advisory. The defensible comparison is to the trading divisions only. Goldman's Global Banking & Markets segment, which is the…