Records should be kept for each investment owned. Retain written purchase and sale confirmation slips for stocks and bonds.

For mutual funds, many financial institutions provide a year-end statement that gives a cumulative summary of activity for the year. This statement is all that is necessary to retain for tax purposes. Otherwise, any statement that shows a purchase, sale, or a reinvestment transaction will need to be retained.

Documentation should be kept for at least six years after a tax return is filed involving those transactions.