that’s a very interesting take, and you’re on the right track, but the math doesn’t quite add up. virtually risk free and 20 - 40% per year cannot both be true at the same time. if a loan is risk-free, competition over the course of a quarter will drive the yield down to the level of treasury bills. the return exists precisely because there is risk. and the risk is real: checking the balance via plaid is a snapshot, not a freeze on funds. ach chargebacks take t+2/3, and dispute resolution under reg e takes up to approximately 60 days. the 2.5% that merchants pay on card transactions is not a “tax on slowness,” but primarily the cost of fraud, chargebacks, and rewards programs. remove the card - the risk remains. where this really works: b2b and m2m payments with verified counterparties, with no consumer protection-related consequences. a small margin, high turnover, and an annual return of 8 - 12%. this is a real business. just not one with a 40% return.