Affirm

Affirm dominates the US buy-now-pay-later market with a market cap of approximately $15 billion and over 18 million active consumers, processing $25 billion in gross merchandise volume annually. Founded in 2012 by PayPal co-founder Max Levchin, it outperforms #4 Klarna by offering transparent, no-hidden-fee loans and eliminating late fees entirely, a key differentiator driving its 30% higher merchant retention rate. Its partnership with Apple Pay in 2023 gave it access to 500 million iPhone users, cementing installment payments as mainstream and accelerating BNPL adoption by 40% among Apple device owners.