Today's late stages financing rounds eclipse IPOs of yesterday's. One reason is inflation - more than 2 times during the last 10 years. Another is that the game has moved one step upstream. In the first boom people inside were caching in at the IPO thus leaving IPO buyers to hold the bug. These buyers think that they have learned the lesson and now they are getting in at the late stages before IPO - thus letting the inside people to cache in and leave these buyers to hold the bug.