The Securities & Exchange Commission on Friday charged Goldman Sachs with defrauding investors by allegedly marketing a financial product tied to sub-prime mortgages without telling them a big hedge fund was on the other side of the trade.

The SEC's civil lawsuit is one of the biggest moves by authorities in response to the financial crisis of 2007-08, and it sent Goldman shares sharply lower. The firm's shares were down about 13% around midday, and the Dow Jones Industrial Average was off more than 1%.