I've been looking for years now for the typical signs of irrational behavior. Maybe because the investing is mostly done by proxy, it's harder for the public to get too excited. They will get their 401k and mutual fund statements for last year soon. Then we'll see. Also, pros have encouraged herd like behavior, saying that people should be invested in stocks vs bonds according to their age, stocks being "risky". Some famous investor/trader once said that the market doesn't care how old you are. So mostly the "pros" are risk averse, perhaps rightly so most of the time. I'm not turning bearish until I see pictures of bulls on the cover of magazines at the checkout counter.
Lowry Research has some very good papers on tops and bottoms. You can D/L some white papers at the link below.
PS Tops are much harder to spot than bottoms.
https://www.lowryresearch.com/Research/WhitePapers