Jim Rickards, a former advisor to the CIA and the Pentagon, warns that the U.S. stock market has become dangerously concentrated in a small cluster of AI-driven names, to a degree not seen in nearly a century. He argues that almost all market gains from the recent bull run are attributable to AI-related stocks, and that stripping them out would leave the S&P 500 worth only a little over half its current value. Rickards notes that AI expenditures accounted for 92 percent of GDP growth, contributing more than all consumer spending combined. He points out that roughly five companies now make up nearly 30 percent of the entire S&P 500, and that a single chip designer recently became the first company in history to be worth $5 trillion, equal to almost 20 percent of all U.S. GDP. Rickards cautions that passive index investors are heavily exposed because eight of the ten stocks anchoring the market are soaring on AI hype, meaning a typical index fund is a heavily weighted bet on those few names.