It is acceptable to put all your eggs in one basket if the basket has been engineered to preserve the eggs through a variety of catastrophes. But in this insta

It is acceptable to put all your eggs in one basket if the basket has been engineered to preserve the eggs through a variety of catastrophes. But in this instance, the single stock is a holding company that is already diversified across several industries. Anything that would negatively impact Berkshire Hathaway to a greater extent than the market as a whole is likely to be the product of intentional malice. As it is now, it's akin to an extremely actively managed mutual fund, in that they generally have at least one seat on the board--or at least VIP seats at the shareholder meeting--for anything they invest in.