No one has ever given a satisfactory explanation of the obvious fact that many successful merchants, manufacturers, or hotel keepers will risk their earnings of years in stock speculation, a business about which they know nothing. These men almost invariably assume stock trading requires no knowledge or study, although they would not think of risking any considerable portion of capital in the expansion of their own business without most carefully canvassing the possibilities of the return to be earned on the funds so expended.
– Robert Rhea, The Dow Theory
