What is active share?

Active share refers to the deviation of the weight of a fund in a portfolio relative to the weight of that same fund in the index. It measures the extent to which a fund deviates from the chosen index, which can help to assess the degree of active management and possible out-performance of the portfolio.

A higher active share indicates a greater deviation from the index and a potentially more aggressive investment strategy. This term is important in the context of portfolio management and investment strategies.