If you look at June 30th, the price high of the day seems to intersect his blue line. At least grossly given the level of detail. Using that to do some back-of-the-napkin calculations means:
Value of blue line = price high = 20420 = 50 dma -(ATR x 5.5)
50 dma was 18739 so solving for ATR value is (20420-18739)/5.5 = 305
Values for different ATRs on 6/30/25
ATR(14) = 260
ATR(21) = 294
Close enough for me, he seems to be using a 21 ATR value. IBD likes that number for ATR also.
Quick rough check, on 7/3 the high of the day pierces the blue line, the high was 20625 and using an ATR 21, the blue line value calculates as 20567 so that fits.
“Guard Rail” blue line = 50 DMA + (ATR(21) * 5.5)
Lakedog