We remember reading in 1916, when U. S. Steel sold up around $136 a share, a prediction that it was going to sell up to $1000 a share. Probably many people who read such news items consider them seriously. Of course, that was a most exaggerated prediction, but during the extreme activity of a bull market, it seems that nearly everybody is talking in exaggerated terms of optimism. That is why most traders seldom ever take their profits in a bull market. They wait until stock prices start to come down, and then they are likely to think there will be rallies, and keep on waiting until they lose all their profits. On the other hand, some people make the mistake of selling too soon. Just because your purchase shows a liberal profit is no reason why you should sell. The stock may have been very cheap when you bought it. In 1920, Peoples Gas sold below $30. Those who bought it then were able to double their money by the close of 1921, and many sold out and took their profits. Of course, if they invested the proceeds in other stocks that were just starting upward, they may not have lost anything, but there was no particular reason for selling Peoples Gas at that time. The public utilities generally were coming into their own, and nearly all of them were regarded by economic students as having unusual opportunities for profit. Then again, it is not always a mistake to sell a stock in order to get funds to put into something else that seems more promising, even though the stock you sell is likely to go much higher. It is very important that you should try to sell your stocks at the right time. That is the main thing to keep in mind and it is better to sell too soon than too late. Don't be too greedy and hold on for a big profit. Read Chapter XXIV. on the "Possibilities of Profit." _PART THREE_ INFLUENCES AFFECTING STOCK PRICES CHAPTER X. MOVEMENTS IN STOCK PRICES It is due to the fact that stock prices constantly move up or down that speculation is possible. Sometimes certain stocks remain almost at a standstill for a long period of time, but at least a part of the stocks listed on the Exchanges move either up or down. If one always could tell just what way they were going to move, it would be comparatively easy to make a fortune within a short time. In the last twenty years, a great deal of time and money has been spent by statistical organizations in checking up statistics for the purpose of ascertaining a definite basis upon which to predict future movements in stock prices. Several of these organizations use very different statistics upon which to base their conclusions, and yet their conclusions are very similar. They have proved beyond any question of doubt that some of these movements are clearly indicated by laws that never fail.