O’Brien Greene engages in relatively little buying and selling, which is called portfolio turnover. If the annual average is 100% portfolio turnover at the average stock mutual fund the figure at O’Brien Greece is 25%. High turnover drives up expenses, and, over the long term, has no corresponding benefit. In recent years brokerage commission levels have fallen dramatically, so much so that they are an immaterial expense. Wouldn’t this argue for higher turnover? It would if high turnover helped performance.