Which type of firm usually has a more complex business model, due to trading on their own accounts?

A market maker typically has a more complex business model because it engages in trading on its own accounts to provide liquidity in the markets. Market makers facilitate trading by offering to buy and sell securities at specified prices, which requires them to manage their inventory of securities and hedge their positions effectively. This trading activity necessitates sophisticated risk management strategies and a deep understanding of market dynamics to ensure they can maintain solvency while meeting the demands of other traders.

In contrast, other types of firms, such as introducing broker-dealers or self-clearing firms, usually do not engage in trading their accounts to the same extent and often focus on facilitating transactions for clients or other broker-dealers. These firms may stick to simpler operational models that revolve around client service, order routing, and market access rather than the complex trading activities conducted by market makers.