They took in the latest $186b in Jan 2015 at a ~ $1b valuation, or about 18.6% of the equity. Assuming the series A was for a similar proportion and that they

They took in the latest $186b in Jan 2015 at a ~ $1b valuation, or about 18.6% of the equity. Assuming the series A was for a similar proportion and that they had some seedfunding and such in '95 it is probably safe to say that the owners got somewhere between 30-50% ownership. With that back of the napkin maths, $500-750m give or take. Considering the the time between series B and acquisition was less than half a year, I say that is a pretty decent ROI.