What if bro is buying more NU

$Bank of America (BAC.US)$ What if Buffett is selling BAC because he is going to add more NU in the future, BAC is already very big which means growth is slow, but NU is relatively new and is not based in USA so it may not suffer as much as BAC if USA enters an economic downturn, suggesting the economy and valuations of US stocks are getting too expensive and Buffett is just being careful and smart to pull out from a mature bank whose economy it mainly operates in may not do so well in the years ahead and instead put it into a new high growth fully digital non USA fintech company he already has shares in