The S&P 500 began dropping on Tuesday and plummetted on Friday, closing with a daily loss of 2.12% and a weekly loss of 3.85%. Today marks the index's largest daily loss since September 2016 (2.45%).

The U.S. Treasury puts the closing yield on the 10-year note at 2.84%.

Here is a daily chart of the S&P 500. Today's selling puts the volume 27% above its 50-day moving average.

Here's a snapshot of the index going back to December 2008.

A Perspective on Drawdowns

Here's a snapshot of record highs and 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.