Even in such a time of madness as the late twenties, a great many man in Wall Street remained quite sane. But they also remained very quiet. The sense of responsibility in the financial community for the community as a whole is not small. It is nearly nil. Perhaps this is inherent. In a community where the primary concern is making money, one of the necessary rules is to live and let live. To speak out against madness may be to ruin those who have succumbed to it. So the wise in Wall Street are nearly always silent. The foolish thus have the field to themselves. None rebukes them.
John Kenneth Galbraith (1955). “The great crash, 1929”