The difficulty of accurate business valuation,

To illustrate the difficulty of accurate business valuation, investors need only consider the wide range of Wall Street estimates that typically are offered whenever a company is put up for sale. 

• In 1989, for example, Campeau Corporation marketed Bloomingdales to prospective buyers; Harcourt Brace Jovanovich, Inc., held an auction of its Sea World subsidiary; and Hilton Hotels, Inc., offered itself for sale. 
• In each case Wall Street's value estimates ranged widely, with the highest estimate as much as twice the lowest figure. 

If expert analysts with extensive information cannot gauge the value of high-profile, well-regarded businesses with more certainty than this, investors should not fool themselves into believing they are capable of greater precision when buying marketable securities based only on limited, publicly available information