It's not the 1920s all over again.
> Of the investment banks that helped SpaceX IPO, Goldman Sachs has their price target at $205 (139x implied price to sales), JP Morgan at $225 (152x implied P/S), Deutsche Bank at $255 (173x implied P/S), Morgan Stanley at $300 (203x implied P/S), and Raymond James at $800 (542x implied P/S). ... I'm guessing you're perfectly fine with this behavior from the largest market participants?
Who do those investment banks sell to? How familiar are you with, for example, Goldman Sachs finding buyers for SpaceX shares? The minimum account requirement at Goldman last I checked was something like $10mm - do you really care if such investors are buying shares in overvalued companies or, like me, declining to purchase?
You are just throwing things around and not providing a coherent argument. Everyday investors don't have to buy these shares. They can continue to follow industry standard advice to buy total market index funds, or target date retirement funds or whatever. Investment banks sell to high net worth individuals who are by definition sophisticated investors - they know and accept the risk of such offerings. So no I don't care even a tiny bit if a Morgan Stanley client decides to buy what you consider to be overpriced shares in a "pump-and-dump" scheme based on your own certainly flawed and unsophisticated valuation of SpaceX or any other company.
And you can just not buy the shares. It's very straightforward.
Sure, but the SEC exists, in theory, to make that decision one you can make an informed decision on, because con artists don't typically put a disclaimer in that says "this is bullshit".