Successful investing professionals are disciplined and consistent and they think a great deal about what they do and how they do it.
Benjamin GrahamNothing important on Wall Street can be counted on to occur exactly in the same way as it happened before.
Benjamin GrahamMathematics is ordinarily considered as producing precise and dependable results; but in the stock market the more elaborate and abstruse the mathematics the more uncertain and speculative are the conclusions we draw there from. Whenever calculus is brought in, or higher algebra, you could take it as a warning that the operator was trying to substitute theory for experience, and usually also to give to speculation the deceptive guise of investment.
Benjamin Graham