Like any group devoted to an idea or philosophy, if the members...

Like any group devoted to an idea or philosophy, if the members ask themselves questions which result in answers incompatible with their doctrine they will (sometimes unknowingly) block it out. Blind and deaf to unwanted facts or information. History has proven this, time over and again.

This behaviour is not very compatible with investing in the stock market IMO. Shareholder sentiment should change when the investment thesis changes. This could involve company valuations, fundamentals and progress, hurdles, stumblings, or any manner of red flags. I'd be interested in hearing any BRN holder's investment theses ('microsoft x10' is not a valid thesis!).

An investor that is not capable of adjusting their sentiment as information changes, is likely no more successful in the stock market than a gambler. Some gamblers strike it big through luck, more do not.

BRN holders are not unlike other market participants, all market theories still apply.