" Conclusion:
Similar-sized bets on PCC and Apple turned out very differently. One became the stuff of legend, the other was written down as a mistake. Although PCC will never reach the heights of Apple, maybe calling it a mistake was a bit premature. Accounting rules were followed conservatively, as they always are at Berkshire, but the economic reality is proving otherwise. It may be that Buffett's mistake was not the price he paid, but that he paid it too soon.

Given the current valuation of the selected peer group, it is hard to see PCC would trade as a standalone entity at a valuation that is lower today than the premium price Buffett paid back in 2016. More importantly, the cash and fundamental aspects of the business do not look impaired now (while they sure did back in 2020). Should business performance continue to improve by profound changes (in particular around power demand), the next few years may prove that perhaps this was one mistake that really wasn't."

seekingalpha.com - Berkshire hathaway a rare buffett blunder that maybe wasnt