Thanks, now I understood

Nice indicator. However, it only works from 2022 onwards, as in earlier bears the previous ATH was only very shortly broken (in 2015, during a short time the April 2013 high was broken, but some see this one as a temporary bull market high), and in 2017/18 it never went below the 2013 high.
The lower difference between the 69k high in 2021 and the 126k high in 2026 may also explain why so many days in 2026 closed below 69k, despite of the lower overall volatility. I think it is only a matter of time until we will reach ATHs and then dip below the previous ATH for a year or so. It would just be "normal" in a context of less volatility.
Take the following example:
- 2027: ATH 150k
- 2028: bear market down to 90k
- 2029: slow recovery, ATH 170k
- 2030: bear market down to 120k (this one would have dipped even below *two* ATHs before)
In this scenario, the difference between highs and lows would be lower each time (2028: 40% crash after the ~55% in 2025-26, 2030: 30% crash) but nevertheless the "days closed below previous ATH" indicator would be triggered in a long stretch of the bearish year.
Still I think your indicator is indeed a point for the theory that we're (or "were") not in a Supercycle but in a less volatile bear market.
Regarding 2019, Cryptopia went bankrupt during the short but quite steep 2019 bull market. But the ETH selloff may indeed have been one of the catalysts of the 2019 bear.