[craftyguy]

> It's fairly rational to point out

Stating that an opinion is rational does not automatically make it rational. Care to explain why you think it is?

[jakamau]

Not the original poster but I would point to the Shiller PE (i.e. CAPE) ratio as a useful indicator of potential over-valuation. The increasing cost required to make the same in earnings is disconcerting.

https://en.wikipedia.org/wiki/Cyclically_adjusted_price-to-e...

http://www.econ.yale.edu/~shiller/data.htm