Today’s range is today’s high minus today’s low.

You can filter stocks by the size their range in dollars, or you can compare today’s range for a stock to its average true range.  Set the min value of today’s range to 200% to see only stocks with a range that is at least twice as broad today as on an average day. Or set the max value of today’s range to 50% to see only stocks with a range today of no more than half their average range.

These filters work from the official highs and lows for the day.  This typically does not update after the market closes.

Today’s range is meaningless before the market opens.  If you set any of these filters, you will not see any alerts in the pre-market.