Guo Sanbin contributed to the c9s/bbgo repository by implementing real-time market data handling and investment validation features using Go. He developed support for parsing Binance TRADE_LITE WebSocket events, introducing a dedicated event struct and robust unit tests to ensure accurate data parsing and guard against regressions. Additionally, he resolved a parameter order issue in Grid2 investment checks, improving the reliability of investment validation logic. His work emphasized clean backend development practices, maintainability, and comprehensive test coverage. Through focused API integration and data parsing, Guo Sanbin enhanced the system’s ability to process live trading events and validate investment parameters.