NOT a good investment portfolio

Concentration risk is through the roof: the top 5 positions represent 2/3 of the total exposure.
Any portfolio this top heavy is exposed to single issuer drawdowns: what every good diversified portfolio should avoid in the first place.
Chances of Apple to experience a regulatory hit or a valuation compression are real, and would cause a volatility spike to the whole portfolio. Such level of concentration is entirely avoidable.

Sector imbalance is huge, with financials dominating, followed by energy. Consumer staples and discretionary do not offset the systemic nature of financials and energy bets. If credit markets tighten or commodity prices move violently, the portfolio moves with them.
No real diversification into countercyclical sectors.

Exposure to genuine growth sector is minimal outside Apple. Long term opportunity cost is therefore high. Missing secular growth is a form of risk.

Geographic concentration is embarrassing, being 100% USA. The whole risk is tied to US monetary policy, regulation, sector cycles.

Portfolio beta is a bit below 1, just because the stocks picked are large and stable.

No hedge against inflation (other than energy) or deflation. No hedge against geopolitical tail risks.
This portfolio lives or dies with the U.S. corporate environment.

There’s no reasoning, no planning, no philosophy behind this portfolio.
In short, it’s a nonsense.

Whose portfolio is this?
Berkshire’s.

Justit said:

Why Berkshire’s has a portfolio like this?
Unlikely they are not aware of all the above… or can it be the case?

Because Mr. Buffett and Mr. Munger were two lucky guys with a lot of cash to invest. The market followed their money, turning their predictions into reality - the "Buffett effect".

I suggest to read chapter 10 of “Fooled by randomness” by N. N. Taleb.
The full book can be found here: Full text of "Fooled By Randomness Nassim Taleb"

I would also love to see @igriv resuming his feud with Taleb here 😏