Overnight: US stocks wavered between small gains and losses as investors monitored a confirmation hearing for Federal Reserve chair nominee Janet Yellen. Treasury prices swung higher as Yellen answered questions. In her testimony, she backed the Fed's current bond-buying program and said she was committed to continuing an accommodative monetary policy. Gold futures rebounded. Nymex oil futures fell after EIA data showed that supplies of crude oil rose for an eighth week in a row, but Brent crude futures rallied after the International Energy Agency said OPEC production fell for a third straight month, in part due to output issues in Libya. European stock markets remained on largely positive ground, as investors awaited testimony from Yellen and after data showed growth, albeit fragile, in the euro-zone region. London BHP up 0.50 %. Rio up 0.48%. New York BHP up 0.46%. Rio down 0.33%. LME Base metals traded lower across the complex.