Assets How much money is invested in a fund.
Size can be a problem, especially for a small-company growth fund.
Those funds often struggle as they get larger. When they are small, they can deliver hot performance by owning just a few stocks that soar. As more money comes in, a fund manager may want to buy more of his or her favorites. That's a big problem for someone buying small-company stocks that don't have a lot of stock outstanding. The manager has to find other stocks to buy, diluting the effect a small number of hot stocks will have on the fund.