Dow theory

Dow theory is used to determine the supply and demand.
Choose a line chart for a company for a duration of 2 years.
First mark the tops and bottoms.
Then mark the highs and lows.
Identify the Higher bottom and higher top(Bullish) or Lower top and Lower bottom(Bearish).
Look at the volume and confirm the trend.
Set long position if bullish and short position if bearish.