I agree, there is no way to exactly predict at what price to sell all one's bitcoin at any particular time. What I am looking for is a disciplined approach I can commit to ahead of time, because it is very hard emotionally to sell when it is increasing parabolically. At the end of 2017 I only sold about 15% of my holdings before the 75% price decline, so next time I want to have price levels I'd update every couple of weeks, where I would sell 10%, 30%, 50% and 70%, maybe up to 90% if it really goes nuts. Then, after the big decline, I would diversify back into bitcoin, maybe 50% of my assets.
Those all sound like fair questions and fair parameters. Selling 15% during the last up cycle to $19,666 was not too bad, either.
Yeah, of course, we saw a subsequent correction of 85% down to $3,122, so even if you had sold a much larger portion of your BTC, it might have been quite difficult to figure out exactly, when to get back in whether in the $10k range, or supra $6k or the ultimate bottom area of the $3,xxx arena. Many folks would likely have gone nearly "all in" in the supra $6k arena, but surely you would have still been better off than hanging onto 85% of your stash, and having only 15% with which to buy back.
I think that almost no matter what you do, you are going to have some difficulties timing comfort points.
Let's take my situation as an example, I tend to sell a small portion all the way UP and then to use my sold BTC proceeds to buy back BTC on the way up. I did not become too anxious about my situation, even though I sold a whole hell of a lot less than you on the way up to $19,666, and I bought back way higher than probably I should have, too, but I don't feel any real regrets. Of course, I tweaked my system a little bit, but I did not make any major changes because largely I am comfortable with whatever level of correction is going to happen, and I feel no need to attempt to second guess or to sell my BTC in the event the price goes up rather than down.
So, in my case, I sold only about 12% on the way up to $19,666, and by the time the price dropped back down to $10k, I had used more than 50% of my sales proceeds to buy back, so in the remainder drop from $10k down to $3k, I used about 40% of the original amount to buy back and by the time we got to the bottom, I only had about 10% in reserve to continue to buy back in the event that the BTC price would continue to fall. I am not exactly disappointed, even though I found some small ways of tweaking to help me to, perhaps, feel a little better on the next go around of UP and DOWN, assuming that they occur again in ways that are a bit difficult to predict, just like the last one had.
So, I guess, my point is that I am changing my price points, percentages and intervals a little bit without any kind of attempt to pinpoint various price points in which to attempt to take larger actions, such as selling more, as you seem inclined to want to do. Also, I am not locked into my tentative plan, so we will see if I change my mind, this time around, and perhaps tweak a bit more than I had previously contemplated. I will admit that there can be some level of reasonable spontaneity in any kind of plan, too. One thing that can make a considerable amount of comfort too, is to have a decent level of equity that has already been built up in the value of the stash that is being held, such as already being 3x, 5x, 10x, 30x or 80x in profits above the initial investment amount.
Based on some of my own mistakes, I think that my highest profit point had never quite reached 20x, but after the 2018 correction, I had never really gone below 4x either, but you can likely recognize a considerable difference between being 20x in profits and 4x in profits, too... but I attempted NOT to let that affect my thinking too much, and part of the reason would likely be to have a decent amount of confidence in the strength of the underlying asset (BTC in this case), which, concededly, is not necessarily an easy kind of psychological posture to maintain.
