The Dow Jones Industrial Average was on track to notch its steepest daily decline in about a month, as selling accelerate in afternoon trade Tuesday. The Dow was off about 600 points, near its nadir, if that level holds it would represent the sharpest drop for the benchmark since the 724-point fall back on March 22. Market participants were broadly attributing concerns about climbing yields, with the benchmark 10-year year Treasury yield touching 3%, as part of the impetus for the added selling pressure. More broadly, the S&P 500 index was down 1.9% at 2,621, the Nasdaq Composite Index declined by 2.3% at at 6,980.