Tested claim

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.

Mayer multiple: price divided by its 200-day average0.2x16.6x201020182026Mayer multiplewhen it fired
Where we are now. Today the Mayer multiple is 1.14 — price is 1.14 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.
No verdict

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 26.3% of the time.

PER CENT OF OCCASIONS FOLLOWED BY THE PREDICTED OUTCOMEWhen it fired25.0%When it did not26.3%8 occasions — too few for a verdict
Mayer multiple above 2.4, scored against a transition-matched baseline
Times it fired8 separate occasions, not days
What followed25.0% a 40% fall within 365 days of that close
Happened anyway26.3% comparable days when the rule did not fire
Difference-1.3 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% against a 26.3% baseline. 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.

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.

We are building that second tool. Until it is here, the Where Things Stand page gives the valuation state and what has historically followed readings like today's, with the sample size attached.

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.