(The Wall Street Journal) -- When British bank HSBC reports third-quarter results for its US business this week, it will provide an early look at what could be in store for US mortgage lenders, banks with big holdings of securities tied to subprime home loans and even the broader US economy. That picture isn't likely to be pretty.

HSBC's American consumer-lending unit, HSBC Finance Corp., is the classic canary in the coal mine when it comes to identifying new problems in the market for subprime loans, or those that were made to borrowers with weak credit.