From “Reminiscences of a Stock Operator” (Jesse Livermore’s thinly disguised as-told-to autobiography – 1923):
Whereupon the average man, who never thinks of values but of prices, and is not governed in his actions by conditions but by fears, takes the easiest way – he stops thinking that there must be a limit to the advances. That is why those outsiders wise enough not to buy at the top make up for it by not taking profits.
Tech stocks, anyone?
Financial Reality 
Comments
That is one of my favorite books, but he did go broke twice and killed himself.
Yes. He struggled with depression all his life. Sad, but so often genius and instability go together.