A DRIP provides the option of immediately reinvesting dividends back into the company, which means that the investor does not receive dividends. The advantage of this is that there will be no brokerage fees or commissions to pay and the investor will not have to wait until he/she has the necessary funds to purchase additional shares. A DIP is a more traditional system where an investor can purchase stock directly from the company, but will only be allowed to sell the stock on predetermined dates and times at a company calculated average market price. One of the subtle aspects of stock purchasing is that one can often purchase stocks without putting down all of the cash up front. This is called “buying on margin,” in effect buying stocks with money borrowed from the broker, with other securities as collateral (typically other stocks in the portfolio). This collateral goes into separate margin account, which typically has some minimum value equal to a proportion of the investment made. If the value of the investment (read: the stock price) falls enough, the buyer receives a “margin call” requiring additional funds, or the margin account is liquidated. Margin buying allows exertion of leverage (proportion of debt to equity backing a position) increasing the consequences of subsequent changes.