Tax may not be an issue at all if FFH decides to swap their BNI to the new BRK-B (split 50 to 1). The split is being done, so that the investors can transfer their BNI holdings to BRK-B holdings without any tax consequences. I have a strong feeling that FFH will opt for this, as they already hold a chunk of BRK-B and will sell at better price or have this as core holding forever.