We sometimes see men who have obtained fortunes, suddenly become poor. […] Frequently it occurs because a man has been engaged in “outside operations,” of some sort. When he gets rich in his legitimate business, he is told of a grand speculation where he can make a score of thousands. He is constantly flattered by his friends, who tell him that he is born lucky, that everything he touches turns into gold. Now if he forgets that his economical habits, his rectitude of conduct and a personal attention to a business which he understood, caused his success in life, he will listen to the siren voices. He says:
“I will put in twenty thousand dollars. I have been lucky, and my good luck will soon bring me back sixty thousand dollars.”
A few days elapse and it is discovered he must put in ten thousand dollars more: soon after he is told “it is all right,” but certain matters not foreseen, require an advance of twenty thousand dollars more, which will bring him a rich harvest; but before the time comes around to realize, the bubble bursts, he loses all he is possessed of, and then he learns what he ought to have known at the first, that however successful a man may be in his own business, if he turns from that and engages ill a business which he don’t understand, he is like Samson when shorn of his locks his strength has departed, and he becomes like other men.
If a man has plenty of money, he ought to invest something in everything that appears to promise success, and that will probably benefit mankind; but let the sums thus invested be moderate in amount, and never let a man foolishly jeopardize a fortune that he has earned in a legitimate way, by investing it in things in which he has had no experience.
"the bubble bursts"
– The Art of Money Getting, P.T. Barnum