"Market Concentration: A Century of Trends and Global Comparisons"

Goldman Sachs' equity strategists led by Ben Snider express concern over the extreme market concentration, with the 10 largest stocks now accounting for 33% of S&P 500 market cap. However, historical analysis by Goldman Sachs shows that despite previous episodes of heightened market concentration, the S&P 500 has often rallied over the 12 months following these peaks. The bank also notes that today's big stocks trade at elevated but not extreme valuations, and the momentum factor remains strong. Additionally, U.S. stock-index futures are mildly mixed, with benchmark Treasury yields dipping, and the dollar lower, while oil prices slip and gold trades around $2,180 an ounce.