Define "portfolio management".

"Portfolio management" refers specifically to the art and science of making decisions about the mix of assets in an investment portfolio. This encompasses a range of activities including asset allocation, security selection, and ongoing management of the mix to align with the investor's objectives and risk tolerance.

Effective portfolio management involves understanding how different asset classes interact, assessing their respective risks and expected returns, and adjusting the portfolio to optimize performance based on market conditions and personal financial goals. It is a holistic approach that aims to maximize returns while managing risk through diversification and strategic decision-making regarding a variety of investment options.

The other options, while relevant to aspects of investing, do not fully encapsulate what portfolio management entails. For instance, creating financial models is more about predictive analytics than managing an actual portfolio. Analyzing market trends for individual securities is a component of investment analysis but does not cover the broader scope of managing an entire portfolio of assets. Focusing solely on stocks disregards the diversification that is often key to effective portfolio management and neglects the importance of including various asset classes to achieve a balanced investment strategy.