Farrell’s error, too low a prediction, stems from gambler’s fallacy. If five tosses for a fair coin all turn out to be heads, what is the probability that the sixth toss will be tails? If the coin is fair, the correct answer is one-half. Yet many people have a mental picture that when a fair coin is tossed a few times in a row, the resulting pattern will feature about the same number of heads as tails. In other words, the representative pattern features about the same number of heads and tails. So, after a run of five heads, people tend to predict tails on the sixth toss, because of the representativeness heuristic. From their perspective, “a tail is due.” But this reasoning is wrong, just as below-average returns are no more likely after “the longest period we’ve ever had with such high returns.”