Stripe rides the online payments boom to a $22.5 billion valuation

Multi-billion dollar payments start-up Stripe just got a new cash injection and a bit more valuable.

The company said this week that it raised an additional $100 million from Tiger Global Management, boosting its valuation to $22.5 billion. This round, first reported by the Information, follows a $245 million Series E fundraise announced last fall that put its valuation at $20 billion.

Stripe has become one of the most sought after payment start-ups in Silicon Valley. It's now one of the most valuable "unicorns" — private firms worth more than $1 billion — in the U.S., beating data analytics firm Palantir's $20 billion water mark. It's by far the most valuable private fintech company, with cryptocurrency exchange Coinbase trailing behind at an $8 billion valuation, according to CB Insights.