In today’s episode of Fintech Stacks, we break down three major moves shaping the global fintech landscape. Klarna goes fully contactless with a tap-to-pay rollout across 14 markets, Nubank prepares to take the leap into full banking status in Brazil, and Fiserv suddenly becomes a magnet for hedge funds and insider buying. We unpack what it all means for payments, digital banking, valuations, and the future of financial infrastructure. Fast, fun, and full of context — your daily fintech briefing starts here.