At that time, the discussion often drew a very bright line between traditional dealers and proprietary trading firms and, in particular, the trading activities associated with each. The distinction between broker-dealers and proprietary trading firms remains important today with regard to why they are trading, but less and less with regard to how they are trading.
Now, as then, broker-dealers intermediate financial transactions primarily to serve their clients’ needs, and, for this reason, they are required to register with FINRA. Conversely, the hallmark of proprietary trading firm activity was and still is high-frequency proprietary trading.