The shares of a publicly traded company are often traded on a stock exchange. The value or "size" of a company is called its market capitalization, a term which is often shortened to "market cap". This is calculated as the number of shares outstanding (as opposed to authorized but not necessarily issued) times the price per share. For example, a company with two million shares outstanding and a price per share of US$40 has a market capitalization of US$80 million. However, a company's market capitalization should not be confused with the fair market value of the company as a whole since the price per share are influenced by other factors such as the volume of shares traded. Low trading volume can cause artificially low prices for securities, due to investors being apprehensive of investing in a company they perceive as possibly lacking liquidity.