That isn’t the asset valuation, that is the range of assessments interested parties make with respect to asset value. Because market clearing transactions are rare in many asset markets, those extremely high variance estimates of asset value are all you have to work with. It is only marginally better than no information at all. Too make matters worse, the rare transactions in these markets frequently have a lot of complicated structure such that the nominal price is not reflective of the underlying value.

tl;dr: Many assets have no meaningfully assessable fair market value. These are investments with extremely long and indefinite time horizons before the asset value can be assessed in a reasonable way. You can look at it as a peculiar type of risk capital portfolio with an extraordinarily long time horizon.