HSBC Holdings Plc triggered the shuttering of trade-finance firm Stenn Technologies after uncovering transactions that were supposed to be with key customers but were potentially bogus instead, people familiar with the matter said. HSBC, which provided Stenn with a revolving credit facility, became concerned that the company's relationships with large customers in Taiwan and Japan may not have been legitimate, the people said. Employees at Stenn believed that much of the London-based firm's revenue came from this group of longstanding clients known internally as "legacy" customers, they said.