FAQ:

[ + ] I dont quite understand what the black line represents. What is the Regression Trend?

A vehicle's regression trend is how the price decreases for all similar vehicles in the market as the vehicles gain more mileage. Using the above chart as an example, notice that when the vehicle has close to zero miles the average market price is about $10,000. However when vehicles in the market have 130,000 miles the average market price drops down to about $3,500.