Despite the sharp and sudden surge in the broader stock market, on the back of some calming of U.S.-China trade tensions, there is no evidence of a buying frenzy, according to the Arms Index, which is a volume-weighted measure of market breadth. The Arms Index tends to fall below 1.000 when the stock market rallies, as the ratio of advancing volume over declining volume tends to increase more than the ratio of the number of advancing stocks over decliners. A drop to 0.500 and below is believed by many market technicians to signal panic-like buying behavior. But while the Dow Jones Industrial Average DJIA, +1.44% swung to a 435-point gain from a loss of as much as 64 points soon after the open, the S&P 500 SPX, +1.48% shot up 1.6% and the Nasdaq Composite COMP, +1.95% jumped 1.9%, the NYSE Arms inched down to 0.907 and the Nasdaq Arms ticked up to 1.064%. The number of advancing stocks outnumbered decliners by 3.12 to 1 on the NYSE and by 2.60 to 1 on the Nasdaq, while volume of advancing stocks topped declining volume by 3.45 to 1 on the Big Board and by 2.44 to 1 on the Nasdaq.