Diversification is key as everything is possible and those that are properly diversify among various asset classes could help subsidize losses in other if things go south. However, we also need to consider that some bubble and irrational exuberance can last much longer than thought especially if supported by these policies we are seeing. I have been expecting a downturn for some time now but have diversified in a way to continue participating in the valuation increases while also allocating some part to cryptocurrencies and precious metals in case of these crisis that can occur.
I like how you say "especially if supported by these policies we are seeing." Indeed!
Right now we've got a bubble in the stock market and real estate, with record personal and national debt levels, stagnant incomes, and meanwhile the Fed is buying bonds and Congress is cutting taxes on the rich!
In short, the government and Fed are acting as if the economy needs to be stimulated BEFORE the bubble pops, so it's just inflating the bubble and setting us up for an even greater pop. Meanwhile another part of that has been interest rates that have been kept low, so don't have much room to be lowered to stimulate the economy once it actually tanks.
So yeah, this is supposed to actually be a self-correcting system, but that only works when our "leaders" play their roles properly. When they see it as a money grab for their rich friends, well we really do need to each be looking out for ourselves, because it's going to be a painful deleveraging.