https://www.reuters.com/article/us-southeastasia-payments-analysis/southeast-asias-mobile-payments-face-shakeout-as-market-booms-idUSKBN1WV2V7 >Just next to Ho Chi Minh City's financial district, two dozen street vendors' stalls display colorful adverts for e-wallets backed by private equity firm Warburg Pincus, ride-hailing firm Grab and Singapore sovereign wealth fund GIC, among others.