Chinese banks are just beginning to disclose their exposure to the U.S. subprime mortgage crisis, sending some bank shares plummeting in Hong Kong.

Bank of China saw its Hong Kong stock price fall by as much as 8.1 percent Friday in reaction to the bank’s report that the bank holds $9.65 billion in subprime asset-backed securities and collateralized debt obligations. That’s 3.8 percent of its total securities investments.