Market risk is the risk that the value of a portfolio, either an investment portfolio or a trading portfolio, will decrease due to the change in value of the market risk factors. The four standard market risk factors are stock prices, interest rates, foreign exchange rates, and commodity prices. The associated market risks are:

As with other forms of risk, the potential loss amount due to market risk may be measured in a number of ways or conventions. Traditionally, one convention is to use Value at Risk. The conventions of using Value at risk is well established and accepted in the short-term risk management practice.

However, it contains a number of limiting assumptions that constrain its accuracy. The first assumption is that the composition of the portfolio measured remains unchanged over the specified period. Over short time horizons, this limiting assumption is often regarded as reasonable. However, over longer time horizons, many of the positions in the portfolio may have been changed. The Value at Risk of the unchanged portfolio is no longer relevant.

Rick Santelli is an American on-air editor for the CNBC Business News network. He joined CNBC as an on-air editor on June 14, 1999, reporting primarily from the floor of the Chicago Board of Trade. He was formerly the vice president for an institutional trading and hedge fund account for futures-related products. He is also credited with being a catalyst in the early formation of the Tea Party movement via a statement he made on February 19, 2009.

In the course of his normal production schedule at CNBC Business, Santelli appears on-air approximately 12 to 16 times a day.

The grandson of four Italian immigrants, Santelli was born near Taylor Street in Chicago's old Italian neighborhood and at age 6 moved with his family to Lombard, Illinois. After graduating from Willowbrook High School in Villa Park, Illinois, Santelli graduated from the University of Illinois at Urbana-Champaign and has been a member of the Chicago Mercantile Exchange and the Chicago Board of Trade. He began his career in 1979 as a trader and order filler at the Chicago Mercantile Exchange in markets that included gold, lumber, CD's, T-bills, foreign currencies, and livestock. While at the University of Illinois at Urbana-Champaign, Santelli joined Alpha Sigma Phi fraternity.