The long-awaited auction of nonperforming mortgages by HSBC USA appears to be underway, though the bank isn’t providing much guidance on the dollar volume of loans it intends to sell this year. In early March, HSBC held a private auction of roughly $1.2 billion of NPLs, according to investors briefed on the sale. “Only a select group of buyers was invited to participate,” said one source. Rumored bidders include Goldman Sachs and Credit Suisse, among others. A spokeswoman for HSBC ...