Should we all buy stock in Nvidia now? It’s not like Peter Thiel is Warren Buffet or anything. And Warren Buffett is buying Alphabet.
Warren Buffett is buying Alphabet out of neceessity - he already sold most of what he could sell and has way too much cash on hand - he just need to buy 'something' - Alphabet seems like the least overvalued big stock out there.
Is he required to buy stock? AFAIK he could just as well hold cash or bonds, and if he believes a bubble pop is imminent (within the next couple months), that would be a responsible move.