I’ve posted about the blue “triangle oscillator” previously.  Its highs correspond to  highs on the btc price chart.  For a long time I’ve also been trying to come up with an algo that identifies the transition from bear to bull.  Finally did it this morning, and it was dead simple:  the red trace equals -1 times the half cycle moving average of the triangle wave oscillator.  In this backtest, a vertical bar marks each transition signal, which comes at the oscillator minimum.  A local minimum marks the dip in the 2021 double top too.  Not that I think I could have traded that signal.  Clear in hindsight but it would have been confusing at the time.

End stage bitcoin bull market Q3 2025



In the chart above, the Triangle Oscillator is nearing a top.   If past is prologue, the bull market's end is approaching. 

As the first chart's horizontal labeling should make clear, this algorithm indexes the price by block height, not by conventional calendar time. The chart below re-indexes by date (while rescaling the oscillator vertically to make the chart more readable).



The extrapolation (red) suggests that the present boom, such as it is, will lose impetus around the end of August. One could reasonably expect a subsequent decline in bitcoin's exchange rate. It's also possible, as a result of declining volatility, that the halvings' influence on price is now so inconsequential that bitcoin's future cyclic declines won't even cancel the natural long term monotonic growth of bitcoin's price, in which case we might simply see many months of choppy sideways price action instead of real bear markets.
Nothing's for sure, as you can tell from looking at 2021. The turn signal came at the first top, then exceeded by a subsequent top, though not by much. Looking back, the way bitcoin's price action rocketed upward in Q4 2020 hinted at something unusual in the offing. This price action, as reflected in the oscillator, wasn't in keeping with expected cyclic behavior (see previous posts for why the oscillator is expected to show a triangle wave in response to regular cyclic price action).  This next chart compares the vagaries of bitcoin's cyclic price action to an ideal triangle wave.



The chart below shows the phase relationship. By the third halving, bitcoin had got well out of phase and responded with some wild swings between block 650000 and 700000. Eventually she settled down. The current cycle has the same phase as Q4 2015, almost like we're back to normal.

It's the one you're calling purple.  The oscillator at the bottom of the chart.
I called it black, though it's actually sort of dark brown.
Everything in my charts seems to imply that BTC will go up.  But I don't know.
All models are wrong, as the saying goes.

In the rainbow channel, the black oscillator is under layered as pale blue.

100 trillion usd... that you, PlanB?

Nah, I just got this done recently. 
Here's a chart I'm hoping is less confusing than the last one.

Hey wachtwoord old friend, long time no see!
I didn't have this algorithm worked out in 2017.  In 2017 I was still feeling my way in the dark.
I got the basic math for the oscillator worked out only last year.  In recent weeks I refined the algorithm more, using trig tricks, and this latest chart is the result.
Here's a chart layout that's a little less confusing, I hope.

If the image looks confusing at first glance, it simply shows bitcoin's price history in green.  The vertical axis is the log, so 3 represents 1000 usd and 4 represents 10000 usd.  Then an oscillator is superimposed, at arbitrary scale in order to show to best effect the correspondence with the price, in blue.

Sine with zero crossings at the halvings, superimposed on a rolling power regression

Chart 1 shows the back-test of the Redneck Fourier indicator for cycle tops.



The log of bitcoin's daily closing price appears in blue, indexed by block height on the horizontal axis. Major grids mark the halvings, which occur every 210,000 blocks. Minor grids on quarter cycle, or about one year. Following the Redneck Fourier indicator, negative zero crossings indicate tops in bitcoin's halving price cycle. The idea in this chart is, wait for the negative zero crossing then sell or go short. But the RF can also be used to forecast.

Choose a rate of increase and draw a straight line, like this



The Redneck shows about when and where the market top is likely to occur, under conditions where bitcoin's price appreciates on that slope. Mark that point where the yellow and blue lines intersect on the graph. Repeat the exercise for different slopes and join the points in a line. Redneck thinks the price is going to bounce off that ceiling.



I performed a back-test of the prognostication function at block 630,000, plugging bitcoin's price history up to that point (dark blue) into the Redneck. The black line shows the Redneck's predicted ceiling. Pale blue shows what actually happened.



I ran the test again at block 650,000

Horizontal axis: block height. Refer to preceding post for the math. Red in positive territory: bull market. Zero crossings (green and yellow) indicate begin and end of bull.

wordpress.com/post/hardworkandlowpay.wordpress.com/852

The next halving (block 840,000) will happen on April 23, 2024.

Bull market when green is above red.



Death crosses where green drops below red indicate major tops.

If anybody's bored and wants something to play with, here's a bash script to estimate the number of days until the next halving

That green trace is the bitcoin usd moving geometric mean over 105,000 blocks, one half cycle.  chart2 below better illustrates the sinusoidal nature of bitcoin's price cycle as its moving geomean swings between peak (pale blue) and trough (red).

Horizontal axis, block height divided by 140. Red, moving geometric mean over 210,000 blocks (one halving). Green, moving geometric mean over 105,000 blocks (half halving). Yellow, their ratio (times 100 to bring it into the frame). Sell signal when the rising half cycle ratio crosses 2; I guess crossing 2 in the other direction indicates buy.  Which we are approaching now.

Answered you on the other forum where we hang out.