Stripe Inc. got an early holiday present today as the payment processing startup announced it has closed a $150 million investment.

Led by General Catalyst Partners and Alphabet Inc.’s recently renamed private equity arm, CapitalG, the funding gives Stripe a mammoth $9.2 billion valuation, according to the Wall Street Journal. That’s nearly twice the valuation it had after its previous $100 million funding round last July.

Moreover, this figure doesn’t account for the $250 million revolving credit facility that Stripe is receiving in conjunction with the financing. The loan comes courtesy of JPMorgan Chase & Co., Goldman Sachs Group Inc., Morgan Stanley and Barclays PLC. Will Gaybrick, Stripe’s chief financial officer, said the new capital will be used to finance strategic acquisitions and expand its service into more regions.

Stripe already maintains offices throughout 25 countries on top of a big presence in the U.S., where half of all Internet users are estimated to have made a purchase from a retailer that uses its service. The firm’s sales numbers are not public, but an anonymous insider told the Journal that its revenue is growing at 40 percent year-over-year. The same source claimed that Stripe is now on track to match the transaction volume handled by Square Inc., the credit card processing company co-founded by Twitter Chief Executive Jack Dorsey.

This success can be credited largely part to the simplicity of its platform, which lets developers process payments in their websites and apps using straightforward application programming interfaces. Consumers don’t see Stripe directly in their transactions, unlike Square.

Stripe recently expanded the lineup by introducing a service called Radar that aims to ease the detection of fraudulent activity. It doubles as an enforcement system that can automatically block suspicious transactions based on factors such as their size, country of and the type of credit card involved. Stripe cofounder John Collison (above left) told TechCrunch at the time of Radar’s launch that more such value-added capabilities are in the works.

Given its rapid growth, new features, and expansion plans, the size of the round isn’t quite as surprising as it otherwise might be. Stripe Cofounder and Chief Executive Patrick Collison (above right) said last year that it takes “a ton of database and distributed-system work” to make the experience easy and secure. “We have a 10-person machine-learning team that works on compliance, risk, fraud, identity verification, all of those things behind the scenes,” he told MIT Technology Review.

The CEO said Stripe is enabling new business models such as crowdfunding and mobile marketplaces such as Lyft and Instacart. “Making it so easy to participate in the online economy has a far larger effect than one might imagine,” he said.

Image courtesy of Stripe