An industry-funded watchdog is beefing up its aging technology as it takes on broader oversight of U.S. stock trading and seeks to manage both a new surveillance program and data-collection system that will usher in an era of big data on Wall Street. The Financial Industry Regulatory Authority is preparing to build the initial phases of a mammoth broker data-collection system in 2015 known as the Comprehensive Automated Risk Data System, or CARDS, pending approval from the U.S. Securities and Exchange Commission. FINRA also is one of 10 bidders to run the consolidated audit trail, or CAT, an industry-wide order-tracking system that will replace an existing FINRA system. The SEC ordered the CAT after it took months for regulators to reconstruct trading during the "flash crash" in May 2010. true The number of people employed by FINRA in technology has grown to about 1,100 from several hundred a few years ago as the regulator won surveillance responsibilities away f