The important thing is where equity earnings yields are in relation to bond yields. So when bond yields are low, stock PE ratios can justify being very high – because the basic equation markets are doing is: what can I get without taking risk, vs what can I get with risk?
The tech boom gave the public a very simple story: PE ratios too high. But equally important was that bond yields hit 6%. If they'd been 1%, stocks would've still been the only game in town.
I feel we wasted a lot of the 2010s talking about CAPE ratios – only for stocks to keep climbing. And that's why Shiller turned CAPE into ECV (Excess CAPE Yield). But this was academia and the media playing catchup to a very simple assessment markets are doing all the time. I think with the 10yr at 4.5%, stocks should be around PE 22.5. Some optimism on AI's immediate effects on margins and investment, and I don't think it's obvious markets are overpriced. I'd still be trying to buy what's out of favour, because future returns certainly could be on the lower side – every year stocks go up 22%, but economies don't grow that fast, is going to exert some kind of pull.
