The quant code libraries of six major Wall Street banks have all been dug up and laid out for everyone to see. Goldman Sachs’ gs-quant alone covers pricing, risk management, and backtesting. That shows top investment banks’ competitive edge no longer comes from how magical their models are, but from years of engineering know-how. Retail traders can use these open-source libraries to build a platform, but what they lack isn’t the tools—it’s the banks’ data pipelines and discipline. Keep an eye on this.