These filters look at the trading range for the previous 5, 10 or 20 days.  These filters report the size of that range.

For example, if the lowest price for a stock last week was $10, and the highest price was $14, then the range would be $4.  You can also express this as a percent, by comparing it to the current price.

These filters always look at the last 5, 10, or 20 trading days.  The range does not count the current day’s prices.