I haven't seen any. Mostly what I've seen cautions that the common knowledge that stocks are down when bonds are up and vice versa has been thrown in utter disarray simply by how much the markets (stocks'n'bonds both) are owned by governments. Something like 80% of Japanese paper is owned by the Bank of Japan. Something like 20% of Apple is owned by Switzerland (they also own more of Facebook than Mark Zuckerberg does). Mostly I see people throwing out "this time it's different" as proof positive that it's never different and it's all going to be the same cycles as always while also throwing out "this time it's different" to point out that interest rates are the lowest they've been in the history of banking and that the mechanisms that have driven investment cycles since the dawn of investment are no longer applicable.
Thanks. My own struggle is looking at my 401k and the 12 month growth and trying to figure out how to avoid a decline I agree is likely. It's tough to understand options and what they mean, but I remember the decline a decade ago. It sucked then, and my 401k is valued significantly higher than it was then.
A harum scarum discussion that I see a lot (and that mk originally posted, and I pooh-poohed, and as is often the case, I'm coming around to his way of thinking) is that ETFs are, effectively, derivative products and that in a period of extreme volatility, they may not act like stocks. They may act like derivatives (tank way faster than the stocks that make them up). A lot of the chatter I'm seeing these days talks about risks/rewards. I pulled everything to cash a year ago. That means I gave up on what? 30% of the market? But if I backtest my portfolio I'd be up like 8%. I wasn't 100% FAANG which is what's driving the tops right now. Instead I'm up 0%. But if things crash, I'm down 0%. Whereas if someone suddenly decides a car company that sells ten thousand cars a year and loses between $4k and $13k on each one of them might not be worth $300 a share, anyone holding Tesla stock might be feeling bad. I have extreme loss aversion. I dump my stuff into things I think are safe. I don't think the market is safe right now, and I don't think there are a lot of opportunities in any publicly-traded company at the moment.