The reader can test his own psychology by asking himself whether he would consider, in retrospect, the selling at 156 in 1925 and buying back at 109 in 1931 was a satisfactory operation. Some may think that an intelligent investor should have been able to sell out much closer to the high of 381 and to buy back nearer the low of 41. If that is your own view you are probably a speculator at heart and will have trouble keeping to true investment precepts while the market rushes up and down.