U.S. stocks start quarter down 2% to 3%, back at levels seen last year; Dow’s off 258 pts

SAN FRANCISCO (MarketWatch)
U.S. stocks tumbled Monday in a pessimistic start to October and the fourth quarter, deepening losses into the close as financials stocks sold off.
The Dow Jones Industrial Average fell 258.08 points, or 2.4%, to 10,6…