Glad to see you made use of the ADX/DMI indicator in your latest newsletter. It's one of my favorites, because it is one of the few mid/long-term indicators that yield a very clear, almost binary signal. Unfortunately "clear" does not necessarily mean "reliable" however, and how reliable mid/long term signals can be is another matter, one which I shall rant on about in my...
Unexpected methodological interlude (you tend to have those yourself, arepo, so you can't complain :D)
The problem with TA indicators when applied to Bitcoin price is always the relative sparsity of data, because we can only look at 2-3 years of data. This problem becomes worse when looking at mid/long term signals, like the weekly ADX signal you presented (because it means we see a lower total number of patterns). If TA is supposed to be different from voodoo (a regular accusation on the wall thread :D), it needs to have an empirical foundation -- that foundation can reasonably only be in the form of frequencies of observation, and resulting estimations of conditional probabilities: out of m patterns observed in total, we have seen pattern X n times, and it is followed by price decline i times, etc, therefore we assume that, given the observation of pattern X, the likelihood of price decline is... etc.
In principle, this is sound methodology. The problem with slow moving indicators is that we have only seen the patterns we speak about 3, 4, maybe 5 times. In the absence of other methods, it is still our best bet to see how those patterns resolved those 3,4,5 times, and trade accordingly, but if we are honest with ourselves, we need to keep in mind that with such low numbers, our predictions don't have much statistical power. This can be slightly ameliorated by seeing how the same indicator performs and behaves in other assets (stocks, currencies), but the problem isn't really solved by that: because Bitcoin is so new, we don't really know for sure which other class of assets is the closest analogue, so conclusions drawn from another asset suffer from the same problem of uncertainty we faced before.
/methodological interlude
Let me add one or two remarks to the ADX analysis you made in the newsletter: you chose a weekly time resolution, which illustrates quite nicely your point on page 13 about the parallel increase of ADX and -DI. In my opinion this point becomes even clearer in a different time resolution however... in my (limited) experience, weekly resolution often tends to paint with too broad a stroke, while daily is often too "jittery", so I noticed that I often get the best results with a compromise: 2d or 3d resolutions:
And here it becomes crystal clear that we currently see something that was absent during the "bubble" of 2013 and the "mini bubble" of 2012: a second downtrend period (-di above +di) following the initial correction after the peak. And, as you pointed out already, this downtrend and rising -di is also coinciding with a rising ADX. So I can't really say I understand the optimism of those who seem to think it will be "business as usual", by which they mean "same deal as 2012 and 2013"... there is an important difference visible on the charts (and in fact, many others as well), and right now, I consider a continued bear market more likely than a trend reversal.