Common stocks should be purchased when their prices are low, not after they have risen to high levels during an upward bull-market spiral.  Buy when everyone else is selling and hold on until everyone else is buying - this is just more than a catchy slogan.  It is the very essence of successful investment.

History shows that the overall trend of stock prices like the overall trend of living costs, wages and almost everything else is up.  Naturally, there have been and always will be dips, slumps, recessions and even depressions, but these are invariably followed by recoveries which carry most stock prices to new highs.

Assuming that a stock and the company behind it are sound, an investor can hardly lose if he buys shares at the bottom and holds them until the inevitable upward cycle gets well under way.

The wise investor realizes that it is no longer possible to consider the stock market as a whole.  Today's stock market is far too vast and complex for anyone to make sweeping generalized predictions about the course the market as such will follow.

It is necessary to view the present day stock market in terms of groups of stocks, but it is not enough merely to classify them as, say, industrials or aircrafts, and so on.  This is an era of constant and revolutionary scientific and technological changes and advances.  Not only individual firms, but also entire industries must be judged as to their ability to keep pace with the needs of the future.

The investor has to be certain that neither the products of the company in which he invests nor the particular industry itself will become obsolete in a few years.