Selling on the NYSE on Wednesday afternoon has reached panic-like proportions, as the exchange's Arms Index rose. The Arms is a volume-weighted breadth measure, that tends to rise when the broader market falls, as the intensity of the selling in declining stocks is usually greater than the intensity of buying in rising stocks. Values above 2.000 are considered panic-like activity. The NYSE ARMS index showed 2,226 decliners for 726 advancers and was at 2.100, and has been hovering around readings of 2.000 or greater late Wednesday, according to FactSet data. So far, selling has been broad based, with the the Dow Jones Industrial Average DJIA, +1.33% trading down 625 points, or 2.4%, threatening to notch its third triple-digit drop in a row. Meanwhile, the S&P 500 index SPX, +1.59% was down 3.1% at 2,656, while the Nasdaq Composite Index COMP, +2.26% , perhaps the hardest hit of the U.S. benchmarks, was down 4.4%. and poised to end in correction territory for the first time in two years. The Dow and S&P 500 also were on the verge of wiping out their 2018 gains.