trailing profits. The risk: any slowdown in AI spending would compress that earnings number fast. - One Stock Now Steers the Entire Market. NVIDIA's market c

trailing profits. The risk: any slowdown in AI spending would compress that earnings number fast. - One Stock Now Steers the Entire Market. NVIDIA's market cap accounts for about 13% of the Nasdaq Composite and 8% of the S&P 500. That is the highest single-stock concentration in the S&P 500 sin…