As of the close of trading on Dec. 13, nine companies boasted market capitalizations of more than $1 trillion. In order of largest to smallest, those companies are:Apple: $3.7 trillionNvidia: $3.3 trillionMicrosoft: $3.3 trillionAmazon: $2.4 trillionAlphabet: $2.4 trillionMeta Platforms: $1.6 trillionTesla: $1.4 trillionBroadcom: $1.1 trillionTaiwan Semiconductor Manufacturing: $1 trillionThe common thread stitching each of these companies together is artificial intelligence (AI). In areas including softwar ...