Identifying Market Participants: Market Makers

In the context of equity markets, understanding the role of various market participants is crucial for grasping how trading dynamics function. Market participants can be broadly categorized into different groups, including institutional investors, retail investors, market makers, and others. Each category plays a distinct role in providing liquidity and facilitating trades.

Which of the following market participants primarily takes on the role of providing liquidity to the market by continuously buying and selling securities, ultimately aiming to profit from the difference between the bid and ask prices?