But getting emotionally attached to particular positions (ideas/trades/etc) is a hallmark of the kind of money-losing paradoxes that humans get themselves into

But getting emotionally attached to particular positions (ideas/trades/etc) is a hallmark of the kind of money-losing paradoxes that humans get themselves into. Being able to step back and be self-critical is extremely important to trading well. Simple example : Suppose you bought Apple stock 2 years ago. It has been a home-run. Do you sell it now? (record your answer). Now look at the facts : You didn't actually buy the stock 2 years ago (most likely). If you said 'sell now' would you short Apple stock now? If you said hold, would aren't you really saying that you should buy it now? It's a trivial example (wrong in many small ways, illustrative as far as the first-order argument goes, IHMO). Of course, if the example is bad : tell me why. The whole point is that not attaching ego to the argument leads to a better discussion : And deeper understanding. And that's what the company is trying to get at.