Big Tech under pressure as Microsoft results put AI costs in spotlight

FILE PHOTO: A Microsoft logo is seen in Los Angeles, California U.S. November 7, 2017. REUTERS/Lucy Nicholson/File Photo

(Reuters) - A number of U.S. big tech companies fell on Wednesday as Microsoft's results signaled how the high-stakes battle for AI supremacy will cost the tech giants that have seen their shares rally in recent months on hype around the technology.

Microsoft's shares fell 3.6% in early trading as the company laid out an aggressive AI-related spending plan, saying deeper investments in AI are required before gains trickle to the bottom line.