Are you saying you don't have all of the information needed to prepare your return?
A lot of times you may not have the cost basis on your 1099-B. You have a few options here.
- Contact your investment brokerage to see if they have the information
- Check your year-end statements. A lot of times more detail is provided there than what is reported on your 1099-B.
- Did you receive statements when investments were purchased? This may be an option if you do not have a lot of sales.
See the attached link for additional way to obtain your basis.
How to find a stock's cost basis