PayPal Holdings Inc. will acquire Honey Science Corp. for about US$4 billion, adding a popular browser extension used to compare prices at online shopping sites.

Honey was profitable in 2018 and has 17 million people using the service each month, PayPal said in a statement. The 7-year-old startup will keep its base in Los Angeles, and the founders will continue to run the business. PayPal shares fell as much as 2.3 per cent in extended trading after the news.

Honey is the payment company’s first major acquisition this year, after a string of deals last year that included Hyperwallet, IZettle and Simility. PayPal has more than US$10 billion of cash, and executives recently had been signaling the company’s openness to acquisitions.

“You can expect us to be acquisitive going forward,” Dan Schulman, the chief executive officer, said on a conference call with analysts this summer. PayPal looks at hundreds of potential deals every quarter, he said, describing acquisitions as “a part of who we are on an ongoing basis.”