Stock market crash? I believe less and less a 1929 style crash is possible. Tesla, Uber, hell, look at GameStop still... The market is rigged. The US and the upper class needs numbers go up, the numbers will go up.
The only way an adjustment to such stock prices would come is if US power and dollar vanes. There is a chance now this will happen, but I guess it will still take a long time.
That doesn't seem plausible to me, though not because I don't think the upper class would be above such behaviour. If investors try to prop up the price of a company, they'll end up buying more over-priced shares and potentially losing far more money in the long-term, so it's probably only worthwhile if they believe that it's just a short-term blip. Also, the investors that don't believe that it's a sensible long-term bet will be offloading their shares to the people who are willing to pay top price for them, so someone is going to end up holding a lot of expensive stock that's not performing.
The only way an adjustment to such stock prices would come is if US power and dollar vanes. There is a chance now this will happen, but I guess it will still take a long time.