Dow Theory (Dow Jones Theory) is a trading approach developed by Charles Dow. This is used to understand the trend of the market/share. To understand the trend of a market/share using Dow theory, minimum 2 years data period to be considered using line charts. During the Bearish trend BUY (Long position) order to be executed. During the Bullish trend, SELL (Short position) order to be executed. At support level buyers are dominating. At Resistance level, sellers are dominating.