According to @EricBalchunas, 10 stocks account for 60% of the S&P 500’s gain this year, signaling a highly concentrated advance in SPX performance, source: Eric Balchunas via X on Nov 13, 2025. He adds that these companies have executed hundreds of acquisitions and that historically a small set of standout firms drives most index returns, source: Eric Balchunas via X on Nov 13, 2025. For traders, this concentration means index-level returns and drawdowns are highly sensitive to moves in the top contributors and risk management should reflect that concentration, source: Eric Balchunas via X on Nov 13, 2025. No direct crypto-market impact was cited in the update, source: Eric Balchunas via X on Nov 13, 2025.