A High-Speed Conundrum

摘要

Global regulators are said to be looking at the wilds swings in the stock market and once again discussing the role played by high-frequency traders in the volatility. With no conclusive evidence of what's causing the dizzying gyrations - 1 percent or 2 percent swings, often during the last half-hour of trading - there's a lot of finger pointing going on. The volatility has been vicious, and while it often has been linked to fears over a European debt default by Greece or signs of a weaker U.S. economy, a precise financial driver has been elusive. On Tues., Oct. 4, in fact, instead of a meltdown, the market had a "melt-up," when the U.S. stock market surged 4 percent without any obvious reason.