Klarna said it will become the exclusive buy-now-pay-later provider at Walmart in the U.S., replacing rival Affirm as the Swedish fintech company nears a potential initial public offering.

Affirm shares are tumbling after rival Klarna, which is preparing to go public in the U.S., said it is now the exclusive provider of Buy Now, Pay Later loans for Walmart.

On the heels of its IPO filing, Swedish fintech giant Klarna announced on Monday that it will exclusively provide buy now, pay later loans for Walmart.