Which role primarily focuses on buying and selling for personal profits or on behalf of others?

The role that primarily focuses on buying and selling for personal profits or on behalf of others is a Trader. Traders are individuals who engage in the buying and selling of securities, commodities, or other financial instruments and are often judged by their ability to generate profits through these transactions. They can work for themselves or for financial institutions, executing trades based on market analysis, strategies, and investment goals.

In financial markets, the behavior and decisions of a Trader are central to the liquidity and efficiency of those markets, as they continuously buy and sell in response to price changes and market conditions. The emphasis on creating profits from trades underscores the Trader's role in navigating market fluctuations.

The other roles mentioned serve different functions within the financial sector. For example, a Sales Trader acts as an intermediary between clients and the trading desk, facilitating trades but not primarily focusing on making profit through trading activities themselves. A Middle Office Manager coordinates operational activities and risk management functions but is not directly involved in trading. A Client Advisor is responsible for managing relationships with clients and providing investment advice, generally without engaging in the trading process themselves. Each of these roles contributes to the financial ecosystem but does not share the same primary focus on trading for profit as a Trader does.