(Reuters) - The U.S. Securities and Exchange Commission is investigating Archegos Capital Management, the family office run by Bill Hwang that defaulted on margin calls earlier this year, Bloomberg News reported on Friday, citing people familiar with the matter. The securities regulator is probing the firm’s trading activity, including whether it concealed the size of its bets on public companies, according to the report. Authorities are also scrutinizing whether Archegos bought multiple stakes in the same companies across several banks to avoid triggering public disclosure rules, the report added. Archegos could not be immediately reached for comment. A spokesperson for the SEC declined to comment. The collapse of the investment firm in March triggered losses of more than $10 billion at some global banks, with Credit Suisse Group AG, Nomura Holdings Inc and Morgan Stanley being the hardest hit. The Archegos meltdown led to calls for more stringent regulation of family offices, which are investment funds set up by wealthy families. In May, SEC Chair Gary Gensler told Congress the commission is considering new trading rules to address problems highlighted by the Archegos blowup. Reporting by Niket Nishant in Bengaluru; Editing by Anil D’Silva Our Standards: The Thomson Reuters Trust Principles.