The sillier the market's behavior, the greater the opportunity for the business like investor.

Even with a margin of safety in the investor's favor, an individual security may work out badly. For the margin guarantees only that he has a better chance for profit than for loss - not that loss is impossible. But as the number of such commitments is increased the more certain does it become that the aggregate of the profits will exceed the aggregate of the losses.

It should be remembered that a decline of 50% fully offsets a preceding advance of 100%.

we have complaints that institutional dominance of the stock market has put 'the small investor at a disadvantage because he can't compete with the trust companies' huge resources, etc. The facts are quite the opposite. It may be that the institutions are better equipped than the individual to speculate in the market.But I am convinced that an individual investor with sound principles, and soundly advised, can do distinctly better over the long pull than large institutions.

Speculators often prosper through ignorance; it is a cliché that in a roaring bull market knowledge is superfluous and experience is a handicap. But the typical experience of the speculator is one of temporary profit and ultimate loss

Most of the time common stocks are subject to irrational and excessive price fluctuations in both directions as the consequence of the ingrained tendency of most people to speculate or gamble... to give way to hope, fear and greed.

The only thing you should do with pro forma earnings is ignore them.