The Nasdaq 100 Index reached a record high, powered by AI-related investments and robust tech earnings, though uncertainties persist around Middle East tensions, inflation, and Federal Reserve policy. Traders added $22 billion into technology-focused ETFs this quarter, compared with $4.6 billion into the broader market, according to Bloomberg Intelligence. Hedge funds also boosted net-long Nasdaq 100 futures positions to their highest level since December. "Investors still feel optimistic about AI given that corporate earnings are really strong," said Jed Ellerbroek, portfolio manager at Argent Capital Management in St. Louis. "But we need to continue to see upward earnings estimate revisions for the biggest tech companies for the rally to continue."

The index gained 0.8% on Tuesday, reversing a 10% drop earlier this year. The S&P 500 is within 0.5% of its record. US equity funds attracted nearly $64 billion in weekly flows through Sept. 16, the most in three months. Cash had its largest outflow in nine weeks.

However, Bank of America strategists warn that investor positioning appears overly bullish relative to profit growth prospects. Market breadth is weakening, with up to 6% of S&P 500 stocks hitting new 52-week lows. Tech megacaps have driven a nearly four-year bull run, with expected 64% profit growth in the information technology group for Q3, far outpacing the S&P 500’s 24%.

Veterans remain cautious, recalling past monetary tightening cycles and the 2022 rate hikes. The rally’s sustainability hinges on continued earnings momentum and Fed policy clarity.