CNBC Daily Open: AI trade frenzy seems driven by a 'virtuous' cycle

Market Performance - The S&P 500 index increased by 2.3% in October, defying historical trends associated with the month [1] - The Nasdaq Composite outperformed the S&P 500, climbing 4.7%, driven by the technology sector [1] Company Highlights - Amazon's shares surged by 9.6% due to strong growth in its cloud-computing unit and high demand in AI and core infrastructure, positively impacting related stocks like Palantir and Oracle [2] - Nvidia reached a valuation of $5 trillion, with its CEO highlighting a "virtuous cycle" in AI that promotes continuous growth and investment [3] Industry Trends - Big Tech companies reported significant increases in capital expenditure, primarily directed towards AI infrastructure, indicating sustained enthusiasm for AI rather than a temporary spike [4]