Price, in other words, is the most efficient collective probability bet about the future. Very rational, indeed.

Markets are very inefficient: Efficient, yes, except when those efficient expressions turn out to be wildly wrong. Note this is not when a trade turns out to be a money-loser. Rather, it's when the analytical framework underlying the trade turns out to be completely unfounded.

This is where our emotional half sends the rational half off the rails. Rather than describing markets as efficient, it is more accurate to describe markets as efficient except when they're not.

Most investors do not know they don’t know: Most explanations of recent market behavior reflect hindsight bias detailing what everyone now knows. It is rare to hear someone asked a question about a market move and not give a detailed after-the-fact explanation. Few are willing to admit that they really don't know or that many market moves are simply random.

Here, Mr. Spock is quite different. He often notes his lack of understanding with a simple response of “fascinating.” His logic and ego control allow the admission of not knowing. He is subject to the Dunning-Kruger effect much less than most. Investors often get into trouble when they imagine they have an understanding about things they don't.

Spock's mixed human-Vulcan heritage was a great plot device that allowed "Star Trek" to subtly comment on the human condition, exploring the tension between logic and emotion, between our intellectual capacities and our baser drives.

Investors who recognize and take account of the Spock market will better understand what is going on, and -- one can hope -- use it to guide their actions for better results.

Barry Ritholtz is a Bloomberg Opinion columnist. He founded Ritholtz Wealth Management and was chief executive and director of equity research at FusionIQ, a quantitative research firm. He is the author of “Bailout Nation.”

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