Everyone was yelling bull market the other day. Today, stocks had worst single-day sell-off since March 16.  DOW ENDS1,861 POINTS, OR 6.9% SandP 500 ENDS5.89% NASDAQ ENDS5.27% RUSSELL 20007.58% VIX ENDS  47.8%  $DJIA $SPX $IXIC $RUT $VIX cross mark down arrow cross mark down arrow cross mark down arrow cross mark down arrow check mark button up arrow