The closest I ever came to a whopping gain was I sold the day before a stock went up 3000% from my buy level. I still made 10%, but although folks say to not sneeze at a profit, you can probably imagine that I was somewhat miffed at having sold LOL ! I remain haunted by that memory till this day.
As the new owners of PINR have a recent success story with EESO which saw a 10000% gain (1 dollar turns into a hundred (not that you can faesibly expect to sell at the top of course)), there is reason to expect a pretty decent gain from the close on Friday and probably from the close in a few weeks time based on their latest super performance.