The gold group was very strong. But presently Guiana began to sag. It declined ten points. That was all right if the pool was marketing stock. But pretty soon the Street began to hear that things were not altogether satisfactory and the property was not bearing out the high expectations of the promoters. Then, of course, the reason for the decline became plain. But before the reason was known I had the warning and had taken steps to test the market for Guiana. The stock was acting pretty much as Chester Motors did. I sold Guiana. The price went down. I sold more. The price went still lower. The stock was repeating the performance of Chester and of a dozen other stocks whose clinical history I remembered. The tape plainly told me that there was something wrong--something that kept insiders from buying it--insiders who knew exactly why they should not buy their own stock in a bull market. On the other hand, outsiders, who did not know, were now buying because having sold at 45 and higher the stock looked cheap at 35 and lower. The dividend was still being paid. The stock was a bargain. Then the news came. It reached me, as important market news often does, before it reached the public. But the confirmation of the reports of striking barren rock instead of rich ore merely gave me the reason for the earlier inside selling. I myself didn’t sell on the news. I had sold long before, on the stock’s behaviour. My concern with it was not philosophical. I am a trader and therefore looked for one sign: Inside buying. There wasn’t any. I didn’t have to know why the insiders did not think enough of their own stock to buy it on the decline. It was enough that their market plans plainly did not include further manipulation for the rise. That made it a cinch to sell the stock short. The public had bought almost a half million shares and the only change in ownership possible was from one set of ignorant outsiders who would sell in the hope of stopping losses to another set of ignorant outsiders who might buy in the hope of making money. I am not telling you this to moralise on the public’s losses through their buying of Guiana or on my profit through my selling of it, but to emphasise how important the study of group-behaviourism is and how its lessons are disregarded by inadequately equipped traders, big and little. And it is not only in the stock market that the tape warns you. It blows the whistle quite as loudly in commodities.