Mr. Market is a term coined by investment guru Benjamin Graham and refers to the concept of the stock market as being fickle and emotional. This person is characterized by dramatic mood swings and can therefore cause stock prices to fluctuate considerably. Graham used this concept to warn investors not to get caught up in the emotions of the market, but instead to continue to think rationally and independently to be successful in investing.

Benjamin Graham was an influential investor whose research in securities laid the groundwork for in-depth fundamental valuation used in stock analysis today. His famous book, The Intelligent Investor has gained recognition as the foundational work in value investing.There are three core concepts, : you’re not buying a stock, you’re buying a business; you have Mr.Market who has all sorts of mood swings and you want to take advantage of Mr.Market when he’s depressed to buy and euphoric to sell; and the third is margin of safety, which is trying to buy things significantly below what they are worth.So Graham's three key ideas are :       1) Looking at stocks as part of a business       2) Mister Market (subject of this site)       3) Margin of Safety