Alphabet said on Tuesday it will spend $75 billion on its AI buildout this year, 29% more than Wall Street expected, while posting cloud revenue that missed analysts' target.The tech giant's shares were down 9% in extended trading.

Alphabet's fourth-quarter earnings day is here, with numbers expected to be released after the markets close Tuesday. This will be followed by an earnings call at roughly 4:30 p.m. ET. The stock has been riding high over the past month as investors grew bullish over Google's AI investment.

The internet giant reported cloud sales that narrowly missed Wall Street’s estimates, worrying investors about the company’s A.I. business.