This morning, news broke that the fast-credit fintech company Klarna has deposed its competitor Affirm as Walmarts exclusive provider of Buy Now, Pay Later (BNPL) loans.Affirm stock (AFRM) dove over 10% Monday morning following the news, before regaining some of those losses. Shares are currently down around 5% as of this writing.According to a press release published this morning, Klarna will be partnering with Walmarts majority-owned fintech startup, OnePay, to exclusively offer installment loans for purchases at Walmart in the United States. The partnership will be available both online and in stores, and will roll out at Walmart checkout this year. Klarnas BPNL services will allow consumers to pay for items purchased at Walmart in installments, with repayment terms ranging from 3 to 26 months.Based on a January report from Capital One, Walmart is the worlds largest retailer above competitors like Amazonmeaning Klarna is about to become a lot more visible to consumers.This is a game changer, Sebastian Siemiatkowski, Klarnas cofounder and CEO, said in the press release. OnePay choosing Klarna as their exclusive installment loans partner at Walmart in the U.S. is a huge vote of confidence as we pursue our goal of being available everywhere for everything.A big week for Klarnaand a rough one for AffirmWalmarts former exclusive BNPL partner was Affirm, Klarnas main rival in the spaceand investors seem to think that the major new deal isnt looking so good for Affirm.In a statement cited by Bloomberg, Affirm shared that its former partnership with Walmart represented about 5% of its gross merchandise volume and approximately 2% of its adjusted operating income in the six months through December.Meanwhile, Klarna is riding high, given that news of its Walmart deal comes just days after the company filed paperwork with the U.S. Securities and Exchange Commission (SEC) related to an initial proposed public offering, a sign that Klarnas IPO could be coming sooner than expected. Although Klarna has not yet set an official IPO date, its now one of the most highly anticipated fintech IPOs this year.