Robinhood's public filing comes one day after it was a fined a record $70 million by FINRA. : (Bloomberg) -- Robinhood Markets Inc. filed for an initial public offering, disclosing it became profitable last year only to have its losses jump in the first quarter, in one of the most high-profile upcoming listings of the year. The company, which pitches its trading platform to novice investors, listed the size of the offering as $100 million, a placeholder that will change when it sets terms for the share sale. Thursday’s registration statement follows Robinhood’s announcement in March that it had filed confidentially to go public.