Microsoft Corp.'s stock MSFT, -2.07% is rallying on Monday, while Apple Inc. shares AAPL, -2.57% are falling, by enough to put Microsoft on track to regain its place as the most valuable U.S. company, after more than three months in second place. Microsoft's stock rose 1.3% to boost its market capitalization to $1.417 trillion, from $1.399 trillion as of Friday's close, while Apple's stock fell 0.3% to knock its market cap down to $1.396 billion from $1.400 billion. The last time Microsoft was the most valuable U.S. company at the market's close was Oct. 30 and Oct. 29. That had snapped a 7-session streak in which Apple was the most valuable. Before that, Microsoft was the most valuable for 127-straight sessions, from April 18, 2019 through Oct. 17. Year to date, Microsoft's stock has run up 18.2% and Apple shares have gained 8.7%, while the Dow Jones Industrial Average DJIA, -1.06% has tacked on 2.1%. Meanwhile, Amazon.com Inc. AMZN, -2.55% was the third most valuable company, as the stock's 2.2% surge boosted the e-commerce giant's market-cap to $1.058 trillion, while Google-parent Alphabet's Inc.'s stock GOOGL, -2.89% tacked on 1.2% to lift its market cap to $1.029 trillion.