Most businesses change in character and quality over the years, sometimes for the better, perhaps more often for the worse. The investor need not watch his companies' performance like a hawk; but he should give it a good, hard look from time to time.

The correct attitude of the security analyst toward the stock market might well be that of a man toward his wife. He shouldn't pay too much attention to what the lady says, but he can't afford to ignore it entirely. That is pretty much the position that most of us find ourselves vis-à-vis the stock market.

The thing that I have been emphasizing in my own work for the last few years has been the group approach. To try to buy groups of stocks that meet some simple criterion for being undervalued-regardless of the industry and with very little attention to the individual company.

Nothing important on Wall Street can be counted on to occur exactly in the same way as it happened before.

The value of any investment is, and always must be, a function of the price you pay for it.

The most realistic distinction between the investor and the speculator is found in their attitude toward stock-market movements. The speculator's primary interest lies in anticipating and profiting from market fluctuations. The investor's primary interest lies in acquiring and holding suitable securities at suitable prices. Market movements are important to him in a practical sense, because they alternately create low price levels at which he would be wise to buy and high price levels at which he certainly should refrain from buying and probably would be wise to sell.

Obvious prospects for physical growth in a business do not translate into obvious profits for investors.