> While Buffett has stated that Berkshire Hathaway will maintain a permanent cash reserve of about $30 billion to fund potential insurance payouts, Bloomstran takes a more conservative approach and adds about $50 billion to that reserve level to account for a full year's worth of potential insurance losses.

From this article in 2024: https://markets.businessinsider.com/news/stocks/warren-buffe...

There is additional context there explaining why Berkshire holding cash reserves is unique to their needs, and historically has only represented 17.5% of their total assets.

Billionaires and large firms are not sitting on piles of cash Scrooge McDuck style, because holding cash is costly.