NovaStar Financial shares fell as much as 63 percent Thursday after the troubled subprime mortgage lender posted a $598 million third-quarter loss and said bankruptcy is possible.

Its stock was down $2.80, or 61 percent, to $1.80 in afternoon trading on the New York Stock Exchange, after earlier falling to $1.72. They began the year at $106.60, after adjusting for a reverse stock split. NovaStar projected a "high likelihood" that its shares will be delisted.