Your rant is based on a wrong understanding of my model.
It has always featured a monthly recalculation of the trend (which for practical purposes does not differ from a running calculation).
Also as you can see from the same link, my model which has the price data from 1/2009 (unlike all the models that arbitrarily ignore the data prior to Mt.Gox, including the one in OP) does very well with the 2011 slump, giving a buy signal at $2.28 (similar signal was given at $71 last summer and at $460 in 2014-3-31).
Let me get this right... You have, by hand, *estimated* the pre-mtgox prices, and then boast that the regression analysis of those made-up prices gives you excellent results for the 2011 bubble?
You've got to be kidding, right? That's not how statistical modeling works.
In case you seriously need an answer to this: if you don't have data for some period, and you have no way to systematically extrapolate data for that period, you don't model that period. The End.
And about the glaring difference between your model and that of jl2012: you're correct that you recalculate the regression as well each month, but you don't *present* it that way. You keep posting the latest regression trend line, and then the discussion is always about that one, and how accurate it is, completely forgetting all the preceding ones.
jl2012's presentation on the other hand is much more "honest" if you want: it shows, in one graph, exactly what his model predicted at time step n, and what the actual price was at time n.
That way, everyone can see, at a glance, where a loglinear regression model was spot on, and where it missed the mark.
Which brings me to the second point...
Either I have subconsciously changed my mind and started to support you, or you have been misunderstanding my stance all along.
This is just too easy... I only need to go your post history of yesterday or so to find the following:
[...]
- Trendline comparison: we are now at -0.367 log units. The trendline is at $993 and rising $7 per day, conclusion: rock bottom
In other words, because we are drastically below the trendline right now, in your words "rock bottom", now is a good time to buy.
What this claim completely ignores however, and which is beautifully visible in jl2012's presentation, is that around October 2011 we hit "rock bottom" as well, but in reality we had about another halving (or more) of price ahead of us, i.e. it would have been well ahead of time to buy back.
It all runs down to the same criticism that applies to all log-linear price based methods:
They are an interesting tool to get an idea of what order of magnitude of price to expect for a given time, but they are *way* off at times, and trading advice of the form "we can only go up now, because: rock bottom" is in no way justified by the accuracy of the model.