Stripe’s funding round was breathtaking for its size and price of $95 billion, amounting to 2.6 times its valuation less than a year ago. But it wasn’t unique. The valuations of the six U.S. startups with the biggest increases over the last year averaged 3.6 times higher than their prior round, according to data compiled for The Information by PitchBook. These include software automation company UiPath and rocket launch company SpaceX.

These leaps in valuations reflect investor confidence that their private investments will result in steep returns when the startups eventually go public. Shares in the Netherlands’ Adyen and in PayPal, two public companies whose business overlaps with that of Stripe, have more than doubled in price in the past year. Shares in Square, another e-commerce peer, are almost six times higher. The steep valuations for private companies also signal that founders of certain fast-growing startups can stay private as long as they choose.