This is not really true. While there were a few hippies who moved to wall st., the reality is that only a tiny percentage of the population were hippies (or their cousins). The "older adults" who made up the 80's/90's culture were, for the most part, the "young adult" members of mainstream culture in the late 60s/70s.

It's just like the way that the 90s mainstream culture in the UK was not based on punks ... not because absolutely no punks "crossed over", but because, as a percentage of the population, there were hardly any punks to start with (just a lot of media noise).