From, The Pitfalls of Speculation (P 49)

Summing up, the man who speculates in a
business-like way trades only in standard properties
with whose history, physical condition,
earnings and prospects he has thoroughly
familiarized himself; forms for himself a careful
estimate of normal value and uses this
value as a gauge by which to decide when
prices are too low and too high ; takes into consideration
also the technical condition of the
market, and does not embark with bad company,
even at low prices ; is not misled by the
thrills of inflation, or the chills of depression;
operates, not for the purpose of gathering a
small profit from many transactions, but to
gather a large profit from a few; trades with
responsible middle-men, and, above all things,
is patient. In short, he maps out for himself
an intelligent and well-founded plan of operation,
contemplating all that may occur, and
having mapped it out, follows it.

Very few speculate in this manner, and
very few succeed.