I'm surprised to not see any current Stripe employees in here commenting on the move. Usually you'd see one of The Brothers Collison in a HN Stripe thread.

As a former Stripe (ex-Stripe?), I do buy the story of running out of room. That office is lovely, but they keep growing on a pretty steep curve, and the floors weren't as dense in there as you might imagine. Decidedly cool interior design tho!