Behemoths Have Dominated the Market Before, but Tech Is Different – WSJ

The five biggest companies by market value are U.S. tech stocks, which now make up more than 15% of the S&P. Is it time to worry that the market is getting top heavy?
— Read on www.wsj.com/articles/behemoths-have-dominated-the-market-before-but-tech-is-different-1528997537