Stocks worsened late Monday with all of the major averages holding modest losses. The Dow Jones industrial average and S&P 500 fell 0.4% each. Both were up as much as 0.5% at session highs. Meanwhile, the Nasdaq lost 0.2%. Volume was again mixed with NYSE tracking higher and Nasdaq running lower. Qihoo 360 Technology (QIHU) cooled off in late trading, paring a nearly 13% gain to 8%. It's still 11% past a 24.40 buy point initially cleared Nov. 20.