Bespoke Investment Group presented a chart showing the relationship of the S&P 500 and its 50 day moving average along with the area that's 3 standard deviations above and below that number. The recent correction of nearly 10% got to the lower mark on the 3 standard deviation level. It helped that there was a big lack of volatility before the market made its recent plunge.
It remains to be seen whether this is a tradable indicator.
Source: Bespoke Investment Group
