One has to account for 1929 gold standard. Since the world has confidence in the US dollar, Uncle Sam can dole out dollars, unlike gold. Just as bull markets are irrational, so are crashes; both are manifestations of herd mentality, as money ebbs and flows.

Today, Vanguard and Fidelity wanted to sell 6M shares of $ROKU after hours through Morgan Stanley. That's how things will go.