The TurboTax online Free edition is used for fairly simple tax return and supports IRS Forms 1040EZ and 1040A.
A tax return with stock sales would not be able to use the Free edition since to report those sales you need the full Form 1040, Schedule D and Form 8949. In tax year 2017 you would need to use the Premier or Self-Employed online editions to report the stock sales. The assumption is that this will also continue for tax year 2018.
Or you could use any of the TurboTax desktop CD/Download editions since all the desktop editions support stock sales.
