I Stock prices change every day as a result of market forces. By this we mean that share prices change because of supply and demand. If more people want to buy a stock (demand) than sell it (supply), then the price moves up. Conversely, if more people wanted to sell a stock than buy it, there would be greater supply than demand, and the price would fall...

The value of a company is its market capitalization, which is the stock price multiplied by the number of shares outstanding. For example, a company that trades at $100 per share and has 1 million shares outstanding has a lesser value than a company that trades at $50 that has 5 million shares outstanding ($100 x 1 million = $100 million while $50 x 5 million = $250 million). To further complicate things, the price of a stock doesn't only reflect a company's current value, it also reflects the growth that investors expect in the future.Earnings are the profit a company makes, and in the long run no company can survive without them. It makes sense when you think about it. If a company never makes money, it isn't going to stay in business. Public companies are required to report their earnings four times a year (once each quarter). Wall Street watches with rabid attention at these times, which are referred to as earnings seasons. The reason behind this is that analysts base their future value of a company on their earnings projection..