US market downturn worsens, Dow drops 660 pts

The Dow Jones tumbled 1.49% or 662 points at 12:01 pm ET. The Nasdaq 100 dipped 0.96%, and the S&P 500 lost 0.88%.The euro added 0.46% compared to the dollar, changing hands at $1.04729 at 12:01 p…