How to make money from retailers’ post-Thanksgiving Black Friday results

Pay no attention to the headlines this week on how retailers’ Black Friday sales are going. History teaches us that these initial sales reports are only randomly related to how retail company stocks perform from Thanksgiving until the end of the year. You might as well flip a coin.

This shouldn’t come as a surprise, since almost all short-term market gyrations are random. But people have an especially hard time accepting this to be true when the media builds excitement to a fever pitch, as it does with retailers’ Black Friday…