COG is an oscillator based on an article by John F. Ehlers on page 20 of the May 2002 issue of Stocks and Commodities Magazine. COG has essentially zero lag and enables clear identification of turning points. This indicator is a result of Ehlers research into adaptive filters. The Investor/RT implementation of COG includes an option to "Volume Weight" the oscillator. When this option is checked, volume will be used in addition to price to weight the indicator.
The Chaikin Money Flow indicator (CMF) is calculated by summing Accumulation Distribution over the given period and then dividing by the sum of volume over the given period, as can be seen in the formula section above. A period of 21 is recommended. The volume is essentially nothing more than volume times change divided by range. A positive CMF value signals accumulation, while a negative CMF value signals distribution. A reference line is drawn at zero to help quickly identify accumulation/distribution regions.
The Arms' Ease of Movement Value (EMV) is a momentum indicator developed by Richard W. Arms, Jr. The indicator takes into account both volume and price changes to quantify the ease (or difficulty) of price movements. The calculation is as follows: EMV = (HI + LO)/2 - (HI1 - LO1)/2 all divided by VOL/(HI-LO) HI, LO, VOL are the high, low, and volume for the current period HI1 and LO1 are the high and low for the previous period The volume is scaled by dividing by a constant divisor, usually 10000. This divisor may be varied by the user in the Arms EMV setup.