These start-ups are changing the way we save, invest, borrow and insure our belongings. : The way we manage our money is changing: We can buy car insurance based on the miles we drive, withdraw money from our paycheck before payday rolls around and apply only for credit cards and loans we know we are likely to be approved for. The start-ups on our annual Fintech 50 list -- like Metromile, Earnin and Credit Karma -- are harnessing data, cutting-edge technology and sheer willpower to overcome the traditional confines of the financial system.