Microsoft shares have biggest single-day drop since March 2020Yesterday, Microsoft reported strong earnings and revenue for its second quarter, but the stock plunged after hours. Investors seem to have been concerned about so much of Microsoft’s booked contracts coming from one company — OpenAI, as well as its slowing cloud growth. Today, it got worse. Microsoft shares sunk 10%, suffering the largest single-day drop since the start of the COVID lockdown in March 2020.