How is the IMV calculated for Private Sellers vs Dealers

This is found under the help link, The CarGurus Instant Market Value IMV is an estimated fair retail price for a vehicle based on a detailed analysis of comparable current and previous car listings in your market. We compute and update our IMV calculations daily using a complex algorithm that takes into account millions of data points including make, model, trim, year, mileage, options and vehicle history. Our IMV is intended to provide pricing guidance but is not an official appraisal or guarantee. What's in our Deal Ratings? To calculate our deal ratings, we compare the asking price of a vehicle to what we estimate to be its fair market value the CarGurus Instant Market Value, and factor in dealer reputation. From this calculation, we rate the quality of the deal: Great, Good, Fair, High or Overpriced. We always show what we believe to be the best deals first based on our algorithm, not how much a dealer pays us. Our Deal Ratings are intended to provide shopping guidance but are not a guarantee of value.