Cheap stock = high risk but also discount

The lower the price of a stock, the more each penny makes a huge impact. It's also very similar to options, as even a penny makes a huge difference in price when the premium is low enough.

However, if we're talking trends, then yes, a huge percentage boost often means higher risks because of the tendency to drop afterwards, as well as the high reward aspect. That's why it's often good to wait until the price drops really low to buy, so your money doesn't fall off a cliff.