Overall Company Performance

• When a company is doing well overall, the value of the stock tends to increase. This is not an iron law -- there may be instances where this does not occur. However, in general, this rule holds true. Signals of good overall company performance include the quality of current and new management, the public reception of a company's product or services and any innovations that the company may be working on.
  
  

Company Earnings

• The earnings of a company are one of the most important factors in determining the value of its stock. Sustained growth in earnings will, over time, tend to contribute to the steady growth in value of a company's stock. However, raw earnings data are not as important as relative earnings. That means that if a company is expected to earn a certain amount of money but fails to meet that target, then the value of that company's stock might actually go down -- even if they did earn some money. This is because the market often expects a company to earn a certain amount.
  
  

Relative Company Performance

• The value of a company's stock is tied not only to its own performance, but to the performance of other companies in its sector or in related sectors. So, the value of the stock of an electronics manufacturer will depend on how well it does against its competition, even if it is a profitable company. The value of its stock might also be affected by related sectors -- as, for instance, furniture companies rely on logging companies. So, good performance by logging companies can contribute to the increased value of a furniture company.
  
  

Geopolitics

• In this era of global interconnectedness, what happens on one side of the world can have a profound impact on the other. The value of a company's stock may be tied to events outside its control or to unexpected events. For instance, inclement weather can damage a company's property or affect the resources it needs to make its product, or a company with a factory in an unstable country might see its stock value decline if unrest occurs in that place.