The DeMark Range Expansion Index is a market-timing oscillator described in DeMark on Day Trading Options, by T.R. DeMark and T.R. Demark, Jr., McGraw Hill, 1999. The oscillator is arithmetically calculated and is designed to overcome problems with exponentially calculated oscillators, like MACD. The TD REI oscillator typically produces values of -100 to +100 with 45 or higher indicating overbought conditions and -45 or lower indicating oversold. DeMark advises against trading in extreme overbought or oversold conditions indicated by six or more bars above or below the 45 thresholds. For more information on using TD REI the user is referred to the DeMark text.
Presentation
Above is a Daily Chart of an AOL May 70 Call (AOO EN). The bold green line in the lower window pane represents the TD REI line, as specified in the preferences below.