As I also get older I've started to grasp the benefits of diversification... or rather, risks of concentration.

And while I appreciate the upside potential of "going all in" and compounding a portfolio at high rates for long periods of time, I think it's extraordinary difficult.

I was wondering if anyone could share their thoughts on proper positioning sizing while maintaining material exposure to high conviction ideas. For example, fellow members of the board have in the past stated they were comfortable with a 50% weight in Berkshire. Why 50%? What would an appropriate baseline weight be for say, GOOGL or MSFT?

I've been thinking that perhaps a fairly valued quality company would have a 5% baseline weight, up to a max limit of 10% if valuations are compelling enough. That way no single position, as compelling as it could be, would at least be kept in check I were wrong in my analysis. But I feel the percentages can vary so much depending on who you ask (some may say 5% is already too large a position, while others would argue a 5% position wouldn't do much).