> they would have missed almost all of the nice long rally that came in the decades after.
I wasn't saying to buy and sell as the ratio goes above/below some specific threshold. More importantly though, this is ultimately cherry picking. You can always look back at historic data and define a start point, or a start and end point, to make an argument work. That has little, if any, weight on predicting what will happen in the future.
I'm being pretty careful here to not claim to know what prices or the economy will look like in the future. I'm simply sharing my read on p/e ratios, what my own take away from they is, and where what I see as historic outliers are.
What do you mean by that?
When I'm investing in a business I want to know how quickly I can get my money back, and how risky I think the investment is relative to my expected gains.
When I'm investing in baseball cards I want to know how much the next person will pay me for it. The stock market seems much more inline with that today, and in any reality where stocks are meant to be considered investment that seems disconnected or entirely unhinged.
Let's talk about a specific company then. Which one have you looked into recently?
Imagine an investor in 1988 (the middle of the p/e chart you linked to) who took your approach. From their perspective, the historical average p/e of the S&P 500 is about 15. Would they have played the market by selling over 15 and buying under 15, they would have missed almost all of the nice long rally that came in the decades after.