Well, they're out there..
1) Contrarian MacroEconomist David Hunter predicts a 65-80% "repricing" (ie: crash) this year - possibly as early as Q2, due to Valuations and the end of a nearly 40 year cycle of decreasing rates.
https://www.peakprosperity.com/a-stock-market-crash-of-65-80-this-year/
2) MacroEconomist Stephanie Pomboy draws similar conclusions..
"Highly-respected economic analyst
Stephanie Pomboy of MacroMavens.com notes that the discrepancy between today’s record financial asset prices and the underlying economy they’re supposed to reflect are the farthest off she’s ever seen in her entire career."
https://www.peakprosperity.com/most-overvalued-stock-market-ever/
I realize that these are just two opinions out of countless others across the entire spectrum from doom and gloom to euphoria, but it IS interesting and perhaps actionable that there are some pretty experienced folks out there raising the alarm that valuations have gotten more excessive than anyone has seen to this point - by a LOT.
I'm candidly pretty darn concerned about valuations at this point, and it would appear the market is starting to be also with some tech stocks already 20+% off their recent peaks (including my former employer - I still hold a small handful of shares of that and the recent 20+% drop has been painful and surprising on how FAST it happened). It also appears that Value stocks are starting to come back into vogue and Growth stocks are going out of favor - at least based on the daily Morningstar charts and what I see happening with various Growth and Value stocks and funds that I hold..
We've had a great run..I'm not so sure that the next 10 years will be anything like the last 10. In fact, I'm for the most part convinced it won't be so am sitting at less than 25% equities and starting to buy inflation protection assets like Gold trust funds and other funds geared toward inflationary environments. That's more a defensive position as I don't expect the 10+%/yr returns on equities to continue, and I do think there's a significant risk that we'll see perhaps not a 65-80% drop as Hunter is forecasting, but could easily see a 30-50% drop in 2021 due to valuations being so incredibly stretched..and I for one don't want to ride that rollercoaster again now that we're in ER..