Stock prices reflect the investors' sentiment about the current outlook of the company. The prices of stocks go up if the fortunes of corporations are positive. This usually means the company has a track record of exceeding the expectations of investors in terms of sales and profit growth. As a result, investors will put a premium on its shares. If the company continuously fails to meet investors' expectations, a discount will be place on its share price.
Stock prices are usually constantly moving. In addition to the company's fortunes, economic and world events can influence the prices of its shares. If the overall conditions of the company's industry are quite promising, the fortunes of most industry should rise. Prices of stocks also allow investors to evaluate the worth of the company relative to sales, assets and earnings.