Portfolio performance refers to how well an investment portfolio is doing in terms of generating returns for its investors. It measures the overall growth and success of a group of assets, including stocks, bonds, mutual funds or other securities, over time. The performance can be evaluated by looking at factors such as total return, capital appreciation, dividend income, standard deviation, Sharpe ratio, and others. Portfolio managers use this information to make informed decisions about buying and selling assets in order to maximize returns while minimizing risk for their clients or investors. In summary, portfolio performance is a key indicator of the health and success of an investment strategy over time.