Microsoft stock closes at a record, topping US$4 trillion in value after a US$1.4 trillion rebound

Microsoft shares closed at a record US$543.45 on Tuesday, giving the company a market value just above US$4 trillion and capping a gain of about US$1.4 trillion since June 25, when the stock closed at US$352.83, its lowest in more than a year.

The rally reverses a rough start to the year. In January, Microsoft lost US$357 billion in a single day, the biggest one-day drop in its history, as investors worried about its AI spending and its reliance on OpenAI, and by midsummer it was the worst performer among the so-called Magnificent Seven tech stocks.

The rebound picked up in late July, when Microsoft reported that Azure grew 43% and topped US$100 billion in annual revenue, sending the stock up 15.5% the next day. It has mostly kept climbing as the company rolled out a revamped Copilot app, a new AI push for Windows and new AI chips.

The broader market has also been setting records, with the S&P 500 closing above 7,800 for the first time last week. CEO Satya Nadella has been urging businesses to keep control of their own data and avoid tying themselves to a single AI model, a pitch that favours companies like Microsoft that run the cloud and workplace software where that data lives.