Pushed to the brink of collapse by the mortgage crisis, Bear Stearns Cos. agreed -- after prodding by the federal government -- to be sold to J.P. Morgan Chase & Co. for the fire-sale price of $2 a share in stock, or about $236 million.

Bear Stearns had a stock-market value of about $3.5 billion as of Friday -- and was worth $20 billion in January 2007. But...