SAN FRANCISCO — Even though high-flying start-ups have met a cool reception on Wall Street in recent months, the willingness of investors to make big bets has not exactly slackened.

Stripe, a start-up that helps businesses do the wonky work of taking payments, announced on Thursday that it had pulled in new investments that gave it a value of $35 billion, making it one of the most valuable start-ups in the world, worth more than prominent names like Airbnb and DoorDash.

The young Irish brothers who founded Stripe have quietly built their company by making it easier for online businesses to take payments from customers and move money around the world.

Payments have long been a fertile territory for internet companies like PayPal and Square because the business can provide a reliable stream of revenue from the 2 to 3 percent charge that is collected on every credit card swipe.