How to trade stocks online?

Penny stocks generally have market caps under $500M and are considered extremely speculative, particularly those that trade on low volumes over the counter. The Securities and Exchange commission warns that, "Penny stocks may trade infrequently, which means that it may be difficult to sell penny stock shares once you own them. Because it may be difficult to find quotations for certain penny stocks, they may be impossible to accurately price. Investors in penny stocks should be prepared for the possibility that they may lose their whole investment."