BRK.A is a conglomeration. Over the past decade they have been in the insurance business (GEICO). But they have also been in other businesses, and I would say t

BRK.A is a conglomeration. Over the past decade they have been in the insurance business (GEICO). But they have also been in other businesses, and I would say that you could consider them like a private equity firm. They would buy companies of good value and build them out. They did it with furniture retail. There is a difference between speculating and investing. Speculating is zero sum and about 80% of the people that trade will lose money. Buffet actually says that diversification is a good idea if you don't know what you're doing. If you can value companies properly then you can have returns greater than the market (beta-weighted). Investing is not zero sum. I'm not going to defend that, it just is. That being said, buy and hold is a dumb idea too. And equities historically beat inflation if you consider dividend payouts.