I believe the only things that really matter in investing are the bubbles and the busts. And here or there, in some country or in some asset class, there is usually something interesting going on in the bubble business. when it comes to the workings of the market, Keynes really got it. Career risk drives the institutional world. Basically, everyone behaves as if their job description is “keep it.” Keynes explains perfectly how to keep your job: never, ever be wrong on your own. You can be wrong in company; that’s okay. For example, every single CEO of, say, the 30 largest financial companies failed to see the housing bust coming and the inevitable crisis that would follow it. Naturally enough, “Nobody saw it coming!” was their cry, although we knew 30 or so strategists, economists, letter writers, and so on who all saw it coming.
But in general, those who danced off the cliff had enough company that, if they didn’t commit other large errors, they were safe; missing the pending crisis was far from a sufficient reason for getting fired, apparently. Keynes had it right: “A sound banker, alas, is not one who foresees danger and avoids it, but one who, when he is ruined, is ruined in a conventional and orthodox way along with his fellows, so that no one can really blame him.” So, what you have to do is look around and see what the other guy is doing and, if you want to be successful, just beat him to the draw. Be quicker and slicker. And if everyone is looking at everybody else to see what’s going on to minimize their career risk, then we are going to have herding. We are all going to surge in one direction, and then we are all going to surge in the other direction. We are going to generate substantial momentum, which is measurable in every financial asset class, and has been so forever. Sometimes the periodicity of the momentum shifts, but it’s always there. It’s the single largest inefficiency in the market. There are plenty of ineffi ciencies, probably hundreds. But the overwhelmingly biggest one is momentum: acting to keep your job is rational. But it doesn’t create an efficient market. In fact, in many ways this herding can be inefficient, even dysfunctional.
via GMO Jeremy Gratham Q4 letter