When a Wall Street analyst or broker expresses optimism, investors must take it with a grain of salt.

A margin of safety is achieved when securities are purchased at prices sufficiently below underlying value to allow for human error, bad luck, or extreme volatility in a complex, unpredictable and rapidly changing world.

Complexity - limits competition.

The risk of an investment is described by both the probability and the potential amount of loss. The risk of an investment-the probability of an adverse outcome-is partly inherent in its very nature. A dollar spent on biotechnology research is a riskier investment than a dollar used to purchase utility equipment. The former has both a greater probability of loss and a greater percentage of the investment at stake.

Many LBOs are man-made disasters. When the price paid is excessive, the equity portion of an LBO is really an out-of-the-money call option. Many fiduciaries placed large amounts of the capital under their stewardship into such options in 2006 and 2007.

The government - the ultimate short-term-oriented player - cannot withstand much pain in the economy or the financial markets. Bailouts and rescues are likely to occur, though not with sufficient predictability for investors to comfortably take advantage. The government will take enormous risks in such interventions, especially if the expenses can be conveniently deferred to the future. Some of the price-tag is in the form of back- stops and guarantees, whose cost is almost impossible to determine.

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.