GlossaryAdvanced
Mass Index
An indicator based on the widening of an asset's trading range, used to identify potential trend reversals through range expansion rather than price direction.
The Mass Index, developed by Donald Dorsey, is calculated from the range between an asset's high and low prices — not its direction — specifically looking for a widening, or "bulge," in that range, which has historically often preceded a trend reversal.
Because it's built entirely from the high-low range rather than closing price direction, the Mass Index is a structurally different approach from most other trend and momentum indicators. See Kaavon's dedicated Mass Index article for the specific "reversal bulge" pattern it's designed to flag.
Examples
- A Mass Index "reversal bulge" pattern is based entirely on the trading range widening and then contracting again, not on which direction price is moving.
- The Mass Index doesn't indicate which direction a potential reversal will go — only that conditions associated with past reversals are present.