[dghlsakjg]

Warren Buffet also does a lot of deals not on the public market. If I'm not mistaken, a minority of Berkshire's money/value is invested in public stock.

This changes the equation somewhat since he can swoop in (dangling a billion dollar check) and do all sorts of research and investments that are unavailable on the open market.

He also (through Geico and other insurance holdings) gets to invest a ton of borrowed money at what amounts to a negative interest rate. (insurance premiums are, in aggregate, a loan to the insurance company until the customers need that money back. With the added benefit that you can repay less than you were given if your business ops are lean enough. That's why Geico pushes to do sales over the phone or internet, much cheaper than agents).

I am, of course, butchering this explanation. If you want an inside look at what he's doing, his letter to shareholders lays it ALL out.

[reducesuffering]

50% of Berkshire's value / market-cap is in public stock. Everything else they own: Geico, BNSF rail, Berkshire energy, etc. each are the actual minorities.