At the heart of today’s market rally are seven companies worth more than most nations' GDP combined. “Magnificent Seven” or Mag 7 is essentially shorthand for the stocks that power Wall Street’s biggest swings. Together, Apple  (AAPL) , Microsoft  (MSFT) , Alphabet  (GOOGL) , Amazon  (AMZN) , Meta Platforms  (META) , Nvidia  (NVDA) , and Tesla  (TSLA) represent nearly $20 trillion in market value and an eye-popping 34% of the S&P 500’s weight. That essentially means when these names jump, the entire mar ...