(Bloomberg) -- US authorities are investigating B. Riley Financial Inc.’s deals with a key client who was linked to a securities fraud, and the use of his assets to help the investment bank obtain a loan from Nomura Holdings Inc., according to people familiar with the matter.Most Read from BloombergFlorida Governor DeSantis Drops Out of 2024 Race, Endorses TrumpHong Kong Stocks at 36% Discount Show True Depth of China GloomMorgan Stanley, JPMorgan Say Buy the Dip After Treasury RoutGloom Over Ch