People with no patience, people who have to sell and people who are day trading and spot something that's moving now that they believe they can score on and so sell to roll into something else. Not everyone has the insight combined with the patience to get in and stay in. They want to chase big gains, and you can't blame them, but it's exhaustive for most as well as much more difficult with some accounts to quickly move large blocks of stock. If they're "iffy" about long term investment, especially in penny stocks,(especially since most pros would, at the most, only suggest that type of investment to close friends or family if they felt strongly bullish on it) then they very quickly get cold feet. If they buy and don't see gains in just a matter of days or weeks, or they see a little red, then they dump the stock like yesterday's trash.