Buffett doesn’t care much about market price, especially those panic selling – “would you sell your house to whatever bidder was available at 9:31 on some morning merely because at 9:30 a similar house sold for less than it would have brought on the previous day?”
Two advantages of controlling companies vs buying non-controlling shares are that: 1) capital allocation, 2) additional tax costs; however, stock market can provide additional return by trading at very low prices.