Rollover to what? Your question doesn't provide enough information. What are the circumstances? What are you talking about?
Seriously, I have an MS in Finance with a minor in Econ, and I haven't a clue what you're asking.
When you sell stock you have cash and you don't have stock anymore. What are you trying to do.
Rollover means Sale and again purchase . Yes you can do it , when you find market is up sell your stocks and as market goes down purchase .