The Economic Times

US stock market concentration risk hits extreme levels: AI stocks surge to 45% of S&P 500 market cap in 2026 can $1.4 trillion AI-linked debt sustain this historic dominance?

US stock market concentration risk hits extreme levels: AI stocks now dominate S&P 500 market cap at a record 45% level in 2026, reflecting a historic shift in US equity markets. Since the launch of ChatGPT, AI-linked companies have surged from nearly 25% to 45% of the index, driven by strong demand for AI chips, cloud computing, and hyperscaler growth. This rise shows how AI stocks dominate S&P 500 market cap as Microsoft, Nvidia, Amazon, Alphabet, and Meta lead earnings expansion across Wall Street. At the same time, AI-linked investment-grade debt has climbed to $1.4 trillion, now representing 15.4% of the US credit market, highlighting deep financial exposure.