Old Growth Harbor LLC

Old Growth Harbor builds its trading systems around reinforcement learning, training agents with algorithms like SAC and PPO rather than the linear factor models most quant shops still lean on. A Quantsys-RL research pipeline feeds a production daemon written on asyncio that executes through Interactive Brokers.

Founded in Seattle in 2024, the firm targets US large-cap equities and ETFs. It is early-stage and quiet, with little public presence beyond its own site, an engineering-first operation built by people who treat trading as a control problem.