Wall Street’s self-funded watchdog fined a unit of Barclays PLC $800,000 for violations related to how the bank reported stock trades over a more than two-year period, hampering the regulator’s ability to properly monitor the market. The Financial Industry Regulatory Authority said late Wednesday that Barclays Capital did not properly update its electronic systems to comply with regulations from August 2009 that required that executing brokers report trades, as well as the name of the executing parties of the trades, to FINRA. As a result, between Aug. 3, 2009 and Dec.