If we have discovered a way of making gold from any old iron, would we tell the world about it? Probably not. We would most likely keep it to ourselves and in the process make ourselves outrageously wealthy. If we found a legal way of picking winners at the racecourse, would we shout it out to everyone? Why would we. We would more than likely keep our mouths shut and quietly make ourselves very rich, very quickly. Of course, nobody has found a way of turning iron into gold or discovered a sure-fire way of picking winners. So, here’s the thing: if we have found a way of accurately predicting the direction of share prices, would we announce it to all and sundry? Again, probably not. Why would we share something as valuable as that with the world. We would most likely bet the farm using our new algorithm over and over again and...