Did you see the headline? “Dropbox raises $250 million based on $10 billion valuation by the BlackRock investment fund.”
Back in 2011, Dropbox also raised $250 million, but on a $4 billion valuation by investors which included Goldman Sachs.
So BlackRock believes that Dropbox is 2.5 times more valuable 3 years later. Which means that Dropbox shareholders gave up 6.25% of their shares to raise $250 million in 2011 and only had to give up 2.5% of their shares to raise an additional $250 million 3 years later.
Could both valuations have been accurate? No. If this proves to be an example of a vastly overvalued company, it will all appear obvious after the fact. Tech bubble or latest greatest? Right now, no outside investor can tell.