That sounds like you are seeking confirmation bias.By that logic...

That sounds like you are seeking confirmation bias.

By that logic a person who buys a stock suddenly goes from having an opinion that is worthless to one that has no value, and someone who sells a stock suddenly has an opinion that instantly turns from valuable to worthless. That makes no sense at all.

Personally, my preference is to ignore a person's holding and look at the quality of their argument. If anything the opinion of people who have sold out should be particularly heeded. The company will only tell pretty stories, nothing about their failings, and people who have sold out will give you the opposite view. That is not to say that they're right, but at least you'll see the other side of the argument and can analyse it and make up your own mind about it.

To my mind that's an awful lot better than being hit from left field and taking a big hit.