Collapsed There have been speculative booms before and since. The capitalists who take part are not stupid. Their system is stupid. Just like the 1920s, the present period has produced in the likes of Calvin Coolidge the illusion that the good times will go on for ever. They are talking about a 'new paradigm' - a whole era of capitalist upswing in the offing.
Older hands know that when that sort of talk starts it's time to sell.
Samuel Brittan has written a couple of articles recently attacking the notion of a new paradigm in the Financial Times - 'Nonsense on stilts' and 'Bubbles do burst'. Share manipulations and the urge to buy shoot way beyond the ability of the real economy to deliver more and more prosperity to the upper classes. As the share boom peaks the speculators look like a load of Hanna and Barbera lemmings who have just run over a cliff and are only held aloft by their own obliviousness to their real situation. But the laws of gravity will assert themselves. What goes up must come down.