HomeFinance & EconomicsInvesting (continued)What is Active Share?
Finance & Economics·2 min·Updated Mar 14, 2026

What is Active Share?

Active Share

Quick Answer

Active Share is a measure of how much a portfolio's holdings differ from a benchmark index. It shows the percentage of portfolio holdings that are not found in the benchmark, indicating the level of active management.

Overview

Active Share is a financial metric that helps investors understand how actively a fund manager is managing a portfolio compared to a benchmark index. It is calculated by taking the sum of the absolute differences between the weights of the portfolio and the benchmark for each stock held. For example, if a fund holds stocks that are not in the benchmark or holds them in different proportions, it will have a higher Active Share, indicating a more aggressive investment strategy. This metric matters because it can give investors insight into the potential for outperformance or underperformance compared to the benchmark. A high Active Share suggests that the fund manager is making significant bets on certain stocks, which could lead to higher returns if those bets pay off. Conversely, a low Active Share may indicate that the fund is closely tracking the benchmark, which could limit potential gains but also reduce risk. Consider a mutual fund that has an Active Share of 80%. This means that 80% of its holdings are different from those in the benchmark index. If the benchmark index performs well, the fund may outperform due to its unique holdings. However, if the benchmark declines, the fund could also suffer greater losses. This illustrates how Active Share can be a useful tool for investors looking to understand the risk and return profile of their investments.


Frequently Asked Questions

Active Share is calculated by summing the absolute differences between the weights of each stock in a portfolio and its weight in the benchmark index. The result is then divided by two, allowing for a percentage that reflects how much the portfolio deviates from the benchmark.
Active Share is important because it helps investors assess how much risk they are taking compared to a benchmark. A higher Active Share indicates a more actively managed portfolio, which can lead to higher returns but also comes with increased risk.
Yes, a fund with low Active Share can still perform well if it closely tracks the benchmark and the benchmark itself performs strongly. However, such funds may not offer the same potential for outperformance that more actively managed funds might provide.