Microsoft shares soared as much as 8% in early trade on Thursday, briefly touching a fresh 52-week high, after the company reported strong quarterly results and highlighted deepening investments in artificial intelligence.Microsoft shares climbed up to 8% in early trade after the company reported $27.2 billion in quarterly profits and emphasized its aggressive investments in AI. The rally propelled its market value past $4 trillion, making it only the second company after Nvidia to reach that milestone.As of 10:09 am ET, Microsoft shares were trading 4.9% up at $538.39. Meanwhile, US markets surged to fresh highs on Thursday, driven by strong tech earnings and continued investor optimism around artificial intelligence, with Microsoft at the forefront of the rally after posting robust quarterly results.The broader market responded in kind. The Nasdaq Composite Index rose 1.3% to 21,396.04, while the S&P 500 advanced 0.8% to 6,413.89. The Dow Jones Industrial Average added 0.3% to reach 44,584.16. Both the Nasdaq and S&P 500 pushed beyond their previous all-time closing highs, AFP reported.Adding to the momentum, President Donald Trump announced a trade agreement with South Korea, introducing a 15% tariff on imports from the country. Markets largely interpreted the deal as a stabilising development, reducing trade uncertainty with a key US economic partner.That helped ease investor concern over inflation data released the same day. The personal consumption expenditures (PCE) price index—the Federal Reserve’s preferred inflation gauge—rose 2.6% year-on-year in June, up from 2.4% in May, signalling ongoing pricing pressure.Among other major tech movers, Meta Platforms, the parent of Facebook, jumped 12.5% after posting $18.3 billion in quarterly profits, with gains led by a strong advertising business and heightened AI investment.