DEFINITION of 'Statement of Additional Information - SAI'
A supplementary document to a mutual fund's prospectus that contains additional information about the fund and includes further disclosure regarding its operations. Also, known as "Part B" of the fund's registration statement.
BREAKING DOWN 'Statement of Additional Information - SAI'
Information contained in the SAI conveys information about a mutual fund that is not necessarily needed by an investor to make an informed investment decision since the prospectus usually provides all of the information needed, in abbreviated form. However, some investors find the SAI useful and although fund companies are not required to provide it, they must give it to investors upon request and without charge.