It's got to have been the most bearish bull market I can remember @topowl

At a guess it may just be expectations for a Fed pivot and a return to a more accommodative stance? Also, lots of excitement for the potential with AI. It's really only a small handful of stocks that are driving the index higher, so that could explain it. Maybe?

A look at the Schiller PE ratio suggests things are hardly cheap

But for the ASX, the (trailing) PE is bang on the long run average:

Who knows! I'm more a "bottom up" guy, but the big picture view is interesting.