Penny stocks can be explosive. Only if you can spot the right stock at the right time. Most penny stocks are pump and dump. Pump and Dump means a promoter hypes the stock. When the stock appreciates and everyone gets in. The promoter dumps it and it falls like a rock. What you need is to be aware of these pump and dumps. Watch this video that shows how to buy a penny stocks before it triples and makes $25K in 3 days! There are over 30K penny stocks out there. The trick lies in finding the stock that is on the verge of a breakout. Get it before the breakout and get out before everyone else.
https://www.youtube.com/watch?v=oBOuUs7aKXU
You should also watch this video tutorial on how to buy penny stocks!