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.

Alphabet will face investor scrutiny over its massive spending on AI when it reports earnings on Tuesday, as revenue growth at the Google parent likely slowed in the holiday quarter due to a slowdown in its advertising and cloud businesses.

CEO Sundar Pichai defended the dramatic increase on a conference call with analysts, who are raising new questions about capital spending.