Historial Spread

 

How do I chart the historical spread on the chart, so that I can get it as a trendline and know at which point the spread increased.


And this will also help me analyze the best trading conditions

 

You will need to capture the tick data yourself


edit> im not 100% sure but ask prices may be downloadable from certain websites, kreslik.com has a list of historical data sources.

Reason: