The past week was a relatively volatile one for our benchmark S&P 500. The big 1.47% Monday gain was wiped out with Tuesday's 1.48% loss. Wednesday was essentially flat, down a fractional 0.06% decline. Thursday perked up with a 1.01% advance, but options expiration Friday erased a third of Friday's gain with a 0.38% loss. The tally for week, however, was in the green with a 0.53% gain over the five sessions.The volatility is largely attributable to mixed messages from the Fed in advance of the September FOMC meeting along with some weak economic data, most notably in Industrial production and Retail Sales.

Interestingly, the yield on the 10-year note closed at at 1.60%, up three basis points from the previous Friday close.

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

Here is daily chart of the index. The index has spent the past six sessions below 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.