How financial 'black swans' may be driving market drops

A sell-off hit the financial markets Monday over Chinese real estate and U.S. federal reserve policy worries. The Dow Jones Industrial Average lost 614 points — a 1.8% drop, its worst since July. The NASDAQ fell 330 points — more than 2%. The S&P 500 lost 75 points, or 1.7%. Both NASDAQ and S&P saw the biggest percentage drops since May. Diane Swonk of Grant Thornton joins Judy Woodruff with more.