William Blair Growth Fund Class I

Over

The fund invests primarily in a diversified portfolio of equity securities, including common stocks and other forms of equity investments (e.g., securities convertible into common stocks), of U.S. growth companies of all sizes that are expected to exhibit quality growth characteristics. It invests primarily in equity securities issued by companies that typically have market capitalizations no smaller than the smallest capitalized company, and no larger than the largest capitalized company, included in the Russell 3000® Index.