When you say retail participation being at a high correlates with bubbly market activity, is that based on recent data? I'm concerned it doesn't take into account the increase in access to the market app based trading has proliferated.

Yes. https://i.ibb.co/8gFNPcwX/temprp.png - Goldman chart.

Luckily we have the lockdown era as a benchmark, when everyone was locked inside and Robinhood style option and stock trading, the SPAC craze, etc, was at mania levels. App proliferation today is close enough to the same as the 2020-2022 period, but it's a good point and sure, a portion of the increase probably does come from further online trading market penetration.