> I don't know if there are other investors than Y Combinator though, there might be one that will push for a sale.
We do have other investors, but (luckily) they're as uninterested in selling as we are. We've always been clear with them that we want to build this for the long-term.
I was linking the article not for showing that they're selling but because it's the first (most recent?) article I found in 2 minutes on Google stating their valuation (one article from 2012 talks about 1bln valuation, btw we're in the same league of Braintree)