The chart below provides a quick snapshot of where the S&P 500 and its ten sectors are currently trading relative to their normal trading ranges. The light green shading represents between one and two standard deviations below the 50-day moving average and is the first "oversold" level. The dark green shading represents between two and three standard deviations below the 50-day. Moves into the dark green shading are considered extremely oversold. The dot is where the sector is currently trading, while the end of the tail is where the sector was trading one week ago.
With this chart, you can easily tell where the sector is now and which direction it has been moving. After Thursday, the S&P 500, consumer staples, energy, financials, telecom, technology, and utilities are all in extreme oversold territory.