In stock trading, PM stands for Portfolio Manager. A portfolio manager is responsible for managing a portfolio of investments, which may include stocks, bonds, and other securities. They work with a team of traders to coordinate and execute trades based on the investment strategy of the portfolio. When one or two of the PMs are out, the lead PM for that stock decides to change their position. It is important to note that PM in stock trading does not stand for Precious Metals Stock, as some sources may suggest.