The S&P 500 opened higher but promptly sold off to its -0.64% intraday low about 90 minutes later. Certainly this morning's weak ISM Manufacturing Report was a factor. But bad news is good news for a Fed dependent market when the news lessens the chance of a rate hike. The index recovered much of its morning loss during the lunch hour and managed to close flat before the big Friday jobs report for August. (Technically the index finished in the red, down 0.004% to three decimal places).

The yield on the 10-year note closed at at 1.58%, up one basis point from the previous close.

Here is a snapshot of past five sessions in the S&P 500.

Here is daily chart of the index. Trading volume was unremarkable, down about 9% from its 50-day moving average.

A Perspective on Drawdowns

Here's a snapshot of selloffs since the 2009 trough.

Here is a more conventional log-scale chart with drawdowns highlighted.

Here is a linear scale version of the same chart with the 50- and 200-day moving averages.

A Perspective on Volatility

For a sense of the correlation between the closing price and intraday volatility, the chart below overlays the S&P 500 since 2007 with the intraday price range. We've also included a 20-day moving average to help identify trends in volatility.