What affects the prices of stocks?

Stocks go up and down because of supply and demand. Prices go up when there are more buyers than sellers. Prices go down when there are more sellers than buyers. 

So what causes the changes in supply and demand? 

Here are a few examples of reasons why a stock can go up in the short term:

• Companies' profits beat expectation

• Introduction of a new product or services

• Generally positive and optimistic market outlook

• New confidence-inducing CEO

• Rumors or expectations of a merger or acquisition.

• Announcement of dividends