I believe this can be done. I might try first, changing the length, doing a few value such as 10,20,50,75,100,200. Also, I have noticed, that a lot of std trends hold up much stronger on a long term lengths compared to what you have right now. You have aggregation period as 1 minute, and length of 21 minutes(since aggregation period is how big every 1 length is). That means that is only scanning the past 21 minutes for this alert. If you change to larger aggregation periods and much larger lengths, you might get some results. I would recommend a length of 50x (or up to 200x or more) the aggregation period so that daily channels will be revealed for the past few hours. The length is the number of aggregation periods that it uses to calculate the channel, so if you have an aggregation period of 1 minute, a length of 21 will only see channels that have gone to lower than -2 std in the last 21 minutes, and this trend, from what I have observed is more valid over long time frames, such as, with lengths that are 90-100 days for recent market conditions(outliers when corona virus began completely changed a lot of sectors to be outside of the 2 std channel.I will try this the next day or two and post results as it is something I have been trying to do and for some reason I didn't think about using the built in stdchannel. Thank you for asking.