[marvin]

By definition you're risking more than 100% of your portfolio value when trading on margin, even short-term. One wrong bet can wipe you out. You shouldn't delude yourself to believe that this isn't the case because you've had one successful experience with it.

Risking getting wiped out may be a palatable prospect if you're early in life and have the time to rebuild your fortune, but it won't be if you're risking 20 years of savings.