The grey line doesn’t appear on the chart. What happened to it, why is grey line missing?

Answer: 

We refer to this as the Fair Market Value line.  That line is calculated with a “linear regression equation” using the sold property data points. If you aren’t seeing a line, it is most likely due to one of three reasons.

1. You may have no sold properties in the list.   
   
2. It may be because there is only one sold property. The math equation requires at least two sold properties to calculate the FMV line. 
   
3. You are trying to build a Listing Chart on unimproved land listings or empty lots. Listing charts can only calculate a FMV line on improved lots with homes that have a sold price and a total square footage.