First, let's define CUSIP. The acronym stands for Committee on Uniform Securities Identifying Procedures (but that really doesn't tell you what it is). A CUSIP is like a stock's serial number. Every stock has one and it's used (along with the 1 to 5 letter ticker symbol and the company's name) to distinguish one stock from another.
There are several things that may cause your stock’s symbol, the company’s name, or the CUSIP ID to change, and it’s usually a result of another corporate action or company reorganization.
When the change becomes effective, the stock with the old symbol, name or CUSIP ID is no longer traded. New shares will appear in your ShareBuilder portfolio as soon as we receive them from the Transfer Agent. You don’t have to do anything but wait for the update.