ACD Meets Market Reality.
Here is a simple exercise to understand this point, particularly if you day trade.
First, let's agree that the 30D NL can stay confirmed for weeks, because it does this all the time when you have a sustained move.
Now, if you have several years of daily data, count the number of instances of 2 consecutive higher daily closes, 3, 4, 5, 6. Do the same for lower. You don't need programming skills for this, I did it in Excel, but be warned many ongoing studies of this nature gobble up RAM, I have 48GB on my workstation, learn programming if you are young enough, LOL.
You will see that while 2 consecutive is common, it starts to fall off sharply by the time you get to 4, 5 or 6. I'm away from the workstation so I can't give you any numbers, just from memory I'm telling you 5 or 6 consecutive are pretty uncommon.
If you are a day trader and you are looking at the 30D and saying it's confirmed positive, I'm going long today, good luck. Try moving averages or MACD crossovers, less work than ACD and you'd probably get similar results when applied mechanically.
You have done the work, you have your number lines, how to use them is a fine art, it is not mechanical. Derivatives that tell you the nuance are where it's at, and it's no secret, Mav has said it before, as have I.
A simple example. The 30D is confirmed, the 5D is weakening rapidly. What time frame are you trading? If longer term, just check for a pullback in progress, where likely support is, and decide what you will do with your stop.
If day trading or just trying to catch short term momentum, I'd be hesitant to go long in that environment. Waiting for the ducks to line up usually gives best results.