Our Private Clients team recently conducted research into the growing concentration of US equity markets. In 2025 year-to-date, just five companies have delivered nearly two-thirds of S&P500 gains, despite representing only 1% of the index. This increasing dominance of a few mega-cap names underscores both the opportunities and risks for investors - participation in them can boost returns but missing them can mean falling behind. Read more as Sean Ashton, Head of Investments at Private Clients by Old Mutual Wealth, explores this trend in detail and explains how they are navigating it, balancing exposure to market leaders with selective opportunities beyond the top holdings to diversify risk and protect client portfolios.