Aug. 4, 2011 -- 11:15 a.m. EDT (Bloomberg) -- A tumble in stocks dragged the Standard & Poor’s 500 Index and the global benchmark gauge down 10 percent from this year’s highs and two-year Treasury yields declined to a record low amid concern that the economy is weakening. The yen pared losses after sliding the most since 2008 against the dollar after Japan sold its currency.