CNBC Daily Open: AI trade frenzy seems driven by a 'virtuous' cycle
1. S&P 500 rose 2.3% in October, defying historical trend. 2. Tech sector boost led by strong AI demand and Amazon's 9.6% gain. 3. Nvidia reached a $5 trillion valuation, indicating AI growth. 4. Big Tech announced significant capital expenditures for AI infrastructure. 5. Overall market sentiment towards AI seems sustainable and positive.