An investment makes money in one of two ways: By paying out income, or by increasing in value to other investors. Income comes in the form of interest payments, in the case of a bondor dividends, in the case of stock. Stock dividends can and do vary. A company has no legal obligation to pay out a dividend, and may have to cut it if earnings fall. On the other hand, unlike with a bond, businesses can raise their dividends when times are good. Most investments are also traded on the marketso that means their value, if you tried to sell them, can rise or fall every day. The most familiar example is with stocks: If other investors see good prospects for higher company earnings or fatter dividends, they may push the price of the stock upwards. Or they may just sense that other investors are feeling more optimistic, and buy simply on the hopes of riding an ebullient market.