The document defines and explains the PEG (Price Earnings to Growth) ratio, which determines a stock's value by taking into account future earnings growth. It is calculated by dividing the P/E ratio by the expected earnings growth percentage. A PEG ratio of 1 suggests the stock is fairly priced based on anticipated growth. PEG ratios above 1 may indicate an overvalued stock due to hype, while ratios below 1 could suggest a stock is undervalued. The document provides examples to illustrate how to interpret PEG ratios and concludes by discussing advantages and disadvantages of the PEG ratio valuation metric.