Worth noting that in very late mega rounds (like the Uber late rounds) there are a lot of odd things going on.

Not only are their preferential shares (which people should know about), but in some cases the investment seems to have been ways of moving and/or washing money.

Things like Chinese investment via investment funds and Saudi money via the vision fund and others can be seen as ways to move from illiquid assets to liquid holdings and these investors are prepared to lose money in that transaction.