Here are the fintech firms changing the way Wall Street works from Forbes' 2021 Fintech 50.: Even before the Coronavirus pandemic closed bank branches and emptied Wall Street’s once-boisterous trading floors, the digitization of all things finance was well underway. Stock markets trade almost entirely electronically and many of Wall Street’s most valuable companies now provide data, technology and software to the big banks, private equity firms and hedge funds that execute the day’s big trades. Covid only accelerated the push for firms to digitize their businesses and handle an increasingly distributed workforce.