Private equity firms have put up some ugly numbers in earnings reports so far. Investors should look past them.

Apollo Global Management, Blackstone Group and Carlyle Group  all reported huge net losses in the first quarter — more than $5bn collectively. Those losses were mainly driven by declines in marks of the on-paper value of their myriad investments. That performance over the long run is what eventually determines the value of these firms. If they can’t ultimately realise gains on their investments they earn less, can’t fundraise and don’t generate fees.