Selling on the NYSE midday Wednesday hit panic-like proportions, based on the so-called Arms Index. The Arms is a volume-weighted measure of market breadth, 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. Closes above 2.000 are considered panic-like.
The Dow Jones Industrial Average lost 264.95 points, or 1.05 percent, to 25,034.97, the S&P 500 dropped 31.73 points, or 1.12 percent, to 2,808.23 and the Nasdaq Composite fell 128.41 points, or 1.63 percent, to 7,742.48.
Most recently, the Arms index was up to 1.752, after jumping above 2 at the session's peak selling period in late-morning trade. The fall in U.S. stocks comes amid heightened fear that a currency crisis in Turkey has the potential of spilling over to emerging markets and other developed markets in Europe.