On a historical basis, yesterday's drop isn't particularly significant. As Eddy Elfenbein at Crossing Wall Street noted, "Last year, the S&P 500 had 48 days in which it closed up or down by more than 1%. In 2015, there were 72. So far this year, there have been seven." In other words, yesterday's fall only feels so large because we've been locked in one of the lowest volatility environments ever for the past few months. Remarkably, the S&P 500 has yet to see a 3% peak-to-trough drawdown since election day, over nine months ago.
Thursday saw U.S. stocks suffer one of their worst sessions so far this year. The benchmark S&P 500 index closed 1.5% lower to represent its biggest one-day drop since May. The sell-off continued in Asia overnight and there was some follow-through in Europe this morning. U.S. index futures have drifted further lower on follow-up technical selling momentum as more bullish speculators have been forced to liquidate their positions.