S&P 500 falls below 200-day moving average

US stocks fell heavily again on Monday. The S&P 500 lost 1.6 percent, closing below its 200-day moving average for the first time since 2012. It has lost 4.8 percent over the past three trading sessions, the worst three-day performance since November 2011.

The Chicago Board Options Exchange Volatility Index rose 16 percent today to 24.64, the highest level since June 2012.

Earlier in the day, the STOXX Europe 600 had closed little changed.

In other markets, Brent crude oil fell 1.5 percent to the lowest since November 2010 but gold rose 0.7 percent.

The latest bout of market weakness was not driven by economic data. Indeed, probably the most significant piece of economic news on Monday was actually positive; China reported that its trade surplus in September more than doubled from the previous year as exports rose 15.3 percent and imports rose 7.0 percent, much better than August's 9.4 percent increase and 2.4 percent decrease respectively.