The S&P 500 Index (SPX) is on pace for its worst three-day stretch in more than a decade
The S&P 500 Index (SPX) got hammered last week, along with its fellow market indexes. In fact, the broad-market barometer dropped 2.1% on Thursday, another 3.2% on Friday, and is poised to surrender yet another 3% today -- which would mark the first time in 13 years the SPX has given up 2% or more in three straight sessions.

Per Schaeffer's Senior Quantitative Analyst Rocky White, this signal could suggest more volatility ahead, if history is any guide. Going back to 1928, this steep a sell-off has happened just 13 times (nine in the Great Depression era), and the SPX has been positive in the subsequent week less than half the time -- compared to 56% of the time under "normal" circumstances. The average one-week loss is 7.3%, compared to a 1.9% anytime loss, while the average one-week gain is 8.7%, compared to 1.7% anytime.
Going out to six months, the SPX has been positive after a steep sell-off 54% of the time, with an average loss of 26.4%, and an average gain of 24.5%. On the flip side, the SPX anytime six-month returns are positive two-thirds of the time, and volatility has been relatively muted, with an average loss of 10.4% and an average gain of 10.8%.
