The Efficient-Market Hypothesis (EMH) is a popular theory within the world of finance. The idea behind EMH is that the stock market is "informationally efficient," meaning that a stock is always accurately valued at any given time based on the information that is publicly available about that stock.
According to EMH, there's no such thing as an "underpriced" stock, and the smartest, hardest-working investment banker at Goldman Sachs Group Inc (NYSE:GS) has no trading advantage whatsoever over the most naive and uninformed home trader.
