Portfolio turnover is an important metric to consider when researching mutual funds. It is important to note that higher portfolio turnover can mean higher fees and incur capital gains taxes that may have to be paid by the investors. It is suggested that potential investors assess the fees and turnover rate of the fund before investing. For example, growth mutual funds and actively managed mutual funds will likely have a higher turnover rate than passively managed funds and vice versa for fees.

Portfolio turnover can be calculated by taking the lesser of the fund's purchases or sales during the period and dividing that number by the average monthly value of the fund's investments. For example, if a fund purchased $50 million of securities during the month, and sold $35 million of securities during the month,and the average monthly value of the fund’s investments was $500 million, then the portfolio turnover rate would be 7% ($35/$500).

In some scenarios, the higher portfolio turnover rate can lead to higher returns, especially when the cost of the fees are lower than the cost of the return. For example, an actively managed fund may purchase a stock that appreciates or have short-term trading strategies that lead to higher returns in the short-term. These funds are willing to incur high fees to purchase and sell securities in the short-term.

In conclusion, portfolio turnover is an important metric to consider when researching funds. This can give potential investors an idea of the fees they may experience and the returns they could receive. It is important to evaluate the fees to see if they are worth the return and make sure the portfolio turnover is working towards the investor goals.