Microsoft (MSFT) produced excellent fiscal Q4 quarterly results on July 30. This included 15% higher revenue on a Y/Y basis and 18% higher free cash flow (FCF). So why is MSFT stock falling? For example, Microsoft generated 36% of its sales as FCF during the quarter ending June 30 (i.e., $23.3 billion in FCF/$64.73 billion in sales). That was higher than last quarter’s 33.9% FCF margins (i.e., $20.965 billion FCF / $61.858 billion in revenue). This was even after Microsoft spent significantly more in capex for its AI-related initiatives. Capex rose from $10.95 billion last quarter to $13.87 bi…