Investors frequently benefit from making decisions with less than perfect knowledge and are well rewarded for bearing the risk of uncertainty. The time other investors spend delving into the last unanswered detail may cost them the chance to buy into situations at prices so low they offer a margin of safety despite the incomplete information

Short sellers age in dog years.

If you can remember that stocks aren't pieces of paper that gyrate all the time --they are fractional interests in businesses -- it all makes sense.

Things that have never happened before are bound to occur with some regularity. You must always be prepared for the unexpected, including sudden, sharp downward swings in markets and the economy. Whatever adverse scenario you can contemplate, reality can be far worse.

A simple rule applies: if you don't quickly comprehend what a company is doing, then management probably doesn't either.

Analysts recommendations may not produce good results. In part this is due to the pressure placed on these analysts to recommend frequently rather than wisely.

The near absence of bargains works as a reverse indicator for us. When we find there is little worth buying, there is probably much worth selling.