Just a week after Brazil’s Nu Holdings Ltd announced a yield of 15% on its high-yield savings accounts in Mexico, Argentina’s Ualá is raising its own by three percentage points to 15%. The speed of the decision highlights the frantic battle for customer acquisition that fintechs and digital banks are waging as they look to grow in Mexico, one of the largest unbanked nations in Latin America. The country has emerged as a key market for financial services startups given that less than 50% of the population has a bank account.