AdrianC thanks for that. So the reserve cash is $30 billion...

I wonder if it has value now with risk free returns at c.5%. But was previously worthless when rates were zero. Not as valuable as the remaining $134 billion, which could some day get deployed at e.g. 9%. But unless float shrunk it is equity like. I'm not really sure.

Doing the above 5 groves analysis has helped me understand valuing Berkshire the way Buffett does (well I think it has helped).

My understanding is that the first 4 groves are assets. The 5th grove, insurance float is an accounting liability. However, Buffett does not think that liability should be deducted from the first 4 asset groves. It's more like equity. Gets replaced every year with new float and in normal circumstances does not get paid out. I previously incorrectly though of float as a 5th grove asset but now I see it as a liability that I don't have to deduct i.e. equity like.

Buffett has also talked about how float could only really decline at 3% p.a.

Getting back to the $30 billion ring fenced cash. I suppose if there was a mega insurance event that caused a huge underwriting loss and huge cash pay out. Then the $30 billion has no value. Given that that is always a possibility, then I guess it makes sense to exclude it.