The Globe and Mail reports in its Tuesday, Nov. 21, edition that major North American stock indexes closed higher on Monday, with Nasdaq's 1-per-cent rally leading the charge as heavyweight Microsoft hit a record high after it hired prominent artificial intelligence executives. A Reuters dispatch to The Globe reports that the Nasdaq boasted its highest closing level since July 31 while the S&P 500 registered its highest close since Aug. 1. The S&P/TSX Composite Index closed at its highest level since Sept. 18. The S&P 500's information technology subindex ended up 1.5 per cent and was the top gainer among the S&P 500's 11 major sectors. Its biggest boost came from Microsoft shares which touched a record high and ended up 2 per cent. Microsoft chief executive officer Satya Nadella said Sam Altman, who headed OpenAI until he was ousted late last week, was set to join Microsoft to lead a new advanced AI research group. Microsoft will also take on Greg Brockman, another OpenAI co-founder, as well as other researchers. The news set a positive tone for the market with other heavyweight technology stocks including Nvidia and Apple also gaining ground.