A theory of market analysis based upon the performance of the Dow Jones Industrial Average and transportation stock price averages. The theory says that the market is in a basic upward trend if one of these averages advances above a previous important high, accompanied or followed by a similar advance in the other. When both averages dip below previous important lows, this is regarded as confirmation of a downward trend. The Dow Jones is one type of market index. (See: NYSE Composite Index)