Stacking timeframes means higher timeframe provides bias, lower timeframes indicate timing.

When is the most optimal kind to buy this weekly pullback? Well, it's when the low time frame ranges are stacked in order with the high time frame ranges. Could you in theory buy while the daily is at a premium? Well, probably because the weekly is in a discount and ultimately we're expecting price to do this. But the most optimal time to buy at the weekly discount is when those lower time frames are stacked in your favor. So ideally, we're stacking your time frames agree. Now, as always, there's going to be exceptions to the rule. There's going to be cases where not everything stacks perfectly because they're not always going to do that. And if you're so selective that you only take trades when every single time frame is in alignment, you're going to have probably a pretty high hit rate, but you're not going to get as many trades.