At the most basic level, there are only two ways you can trade stocks; you either buy them or you sell them.

If you think share prices are going up, you buy. You close your position by selling the shares.

You can also bet on falling share prices by selling short. That is, selling shares you do not own. You essentially borrow shares from your broker and then sell them. You close your position by buying back the shares (buy to cover) and giving them back to your broker. Typically, not all stocks can be shorted, depending on the inventory of shares your broker holds.

On sharewise, you can carry out buy, sell, short or closing trades in your virtual portfolio via the help pages.

To find out about some more sophisticated trading techniques, see the article: Advanced Trade Types.