Is a Mayer multiple above 2.4 an overheated market?
Price at 2.4 times its 200-day average indicates an overheated market due to correct.
Where we are now. Today the Mayer multiple is 1.15 — price is 1.15 times its 200-day average, against a threshold of 2.4. Shaded bands are the 8 occasions the rule fired, the same ones counted in the table below: 2011-03, 2012-08, 2013-03, 2013-11, 2017-06, 2017-11, 2019-06, 2021-01.
This rule has fired 8 times. A 40% fall followed within a year on 2 of the 8. On comparable days when it did not fire, a 40% fall followed 27.0% of the time.
| Times it fired | 8 | separate occasions, not days |
|---|---|---|
| What followed | 25.0% | a 40% fall within 365 days of that close |
| Could plausibly be | 9% to 54% | the range the true rate could take, on this many occasions, before you invoke anything but chance; a binomial interval that treats the episodes as independent trials |
| Happened anyway | 27.0% | comparable days when the rule did not fire |
| Difference | -2.0 pts | near zero means the signal added nothing |
Where the claim comes from
Trace Mayer's ratio, with 2.4 chosen as a historically unusual level.
How we tested it
Trigger: price / 200DMA above 2.4. Scored as a top rule: 40% fall within 365 days.
Only days the rule could have fired are counted. Consecutive triggers within 90 days are one occasion. The baseline excludes each trigger and the 90 days after it, because the aftermath of a signal is not a fair comparison. No verdict is given below 20 occasions.
What the numbers say
Eight occasions. 25.0% followed by a 40% fall within a year, against 27.0% on comparable days when the rule did not fire: a 2.0-point gap, negative, on 8 observations. Essentially no difference, on a sample too small to detect one anyway.
What this does not mean
The threshold was chosen by looking at history, which makes any apparent edge partly circular. Our test cannot correct for that.
And it does not mean the threshold itself was chosen fairly. Every rule in this registry was specified by someone who had already seen bitcoin’s history, so the cut-off is fitted to the record it is being judged against. The interval above measures sampling variation between independent trials and nothing else: not the choice of threshold, not that cycle turns are few and related, and not that thirty-six rules were tested in total. Only the forward record, which fixes a rule before its answer is known, avoids this.
What would change the answer
More occasions, and a threshold set before rather than after the fact.
If you cannot time it, the question changes
Most of the claims in this registry cannot be shown to beat a coin flip, and several are worse than one. That is not an argument against holding bitcoin. It is an argument that the decision worth spending effort on is how much to hold, not when to buy.
That is what How much bitcoin? is for: what fixed weights actually did in a conventional portfolio, and how much the answer depended on the year you started. For the valuation state today, and what has historically followed readings like it, see Where Things Stand.
Recomputed from the daily public snapshot by fetch/scorecard.py and published as scorecard.json. Method on the methods page; every claim in the scorecard.