In order to buy a stock, bond or any other type of security (see below), you need a stock broker. A stock broker has access into the stock exchanges where stocks are bought and sold and matches your order (as a buyer or seller) with another investor’s order (who is in turn selling or buying). Once you open up an account such as a Roth IRA, traditional IRA, 401k, etc. (see our previous article on account types) and deposit money into your account you can start investing your money by purchasing different securities.