By one metric, investors would have to go back 75 years to find the last time the S&P 500's losses were this abrupt.
Bespoke Investment Group observed that the S&P 500 has closed more than four standard deviations below its 50-day moving average for the third consecutive session. That's only the second time this has happened in the history of the index. May 15, 1940, marked the end of the last three-session period in which this occurred:
This string of sizable deviations from the 50-day moving average is a testament to just how severe recent losses have been compared to the index's recent range.
"Not even the crash of 1987 got this oversold relative to trend," writes Bespoke.
The money management and research firm produced a pair of analogue charts showing what's in store if the S&P 500 mimics the price action seen in mid-1940. Overlaying the axes gives the impression that the worst of the pain is behind us, and a market bottom isn't too far off:
However, indexing the S&P 500 to five sessions prior to the tumult shows that a replication of the mid-1940 plunge could see equities run much further to the downside and into a bear market:
If it tracked the 1940 trajectory, the S&P 500 would hit a low of 1,556 in relatively short order. But Bespoke doesn't think stocks are fated to repeat that selloff.
"There is nothing, nothing, we have seen - Chinese fears, positioning, valuation, or any other factor - suggests to us that we are headed to 1556," the analysts write. "More likely, in our view, is something along the lines of the top analogue; we doubt the bottom is in, but see it unlikely we enter a bear market and a true stock market crash."