An AI (Artificial Intelligence) sign is seen at the World Artificial Intelligence Conference (WAIC) in Shanghai, China July 6, 2023. REUTERS/Aly Song/File Photo BOSTON, Aug 3 (Reuters) - Massachusetts securities regulators have opened an investigation into the ways in which investment firms use artificial intelligence in their interactions with investors, citing concerns about the technology's potential unchecked use. Massachusetts Secretary of State Bill Galvin, the state's top securities regulator, on Thursday announced that his office had sent letters of inquiry to a number of firms using or developing AI for their businesses, including JPMorgan Chase (JPM.N) and Morgan Stanley (MS.N)....