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.

The function of the margin of safety is, in essence, that of rendering unnecessary an accurate estimate of the future.

The stock market resembles a huge laundry in which institutions take in large blocks of each others washing ... without rhyme or reason.

We have been trying to point out that this concept of an indefinitely favorable future is dangerous, even if it is true; because even if it is true you can easily overvalue the security, since you make it worth anything you want it to be worth. Beyond this, it is particularly dangerous too, because sometimes your ideas of the future turn out to be wrong. Then you have paid an awful lot for a future that isn't there. Your position then is pretty bad.

No matter how careful you are, the one risk no investor can ever eliminate is the risk of being wrong. Only by insisting on what Graham called the "margin of safety" - never overpaying, no matter how exciting an investment seems to be - can you minimize your odds of error.

The intelligent investor is likely to need considerable will power to keep from following the crowd.

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.