These alerts appear any time there is a print for a higher or lower price than the rest of the day.  Highs and lows are reset once a day at a time determined by the exchange.

When the alerts server sees a new high, it looks for the most recent day before today when the price was higher than it is now.  It reports the day when this happened, and the high for that day as resistance.  For a new low, the server looks for the most recent day when the price was lower than the current price.  It reports the low for that day as support.  Note:  This is a very simple version of support and resistance based only on daily highs and lows.  Several alerts listed below implement more advanced algorithms for finding support and resistance.

These alerts are related to the Position in Range filters.  Use these filters to make other alert types sensitive to highs and lows.

More options related to these alerts are listed below.