Cramer's lightning round: Cannabis ETFs have pulled down GW Pharma

Cramer's lightning round: Cannabis ETFs have pulled down GW Pharma

"Mad Money" host Jim Cramer rings the lightning round bell, which means he's giving his answers to callers' stock questions at rapid speed. For exclusive access to video from CNBC check out CNBC PRO: https://www.cnbc.com/pro/?__source=yo...