Fisk

Fisk runs your trading strategies as composable rules over the platform's market event stream and drives paper positions with real protection: stops, take-profits, trailing stops, and per-account risk limits. Because everything is an event, a backtest over replayed history and the live feed are the same code path — a strategy that backtests IS the strategy that trades. Fisk never touches an exchange: order execution is a separate, later component; fisk owns the decisions and the record of why.