Alphabet shares fell 8% on Wednesday as investors balked at the Google parent's slowing cloud growth and planned $75 billion capital spending for the year, underscoring growing fears over Big Tech's escalating artificial intelligence costs.

Alphabet shares dropped after the search giant fell short of Wall Street's fourth-quarter revenue expectations and announced big spending plans

Alphabet shares fell more than 9% in after-hours trading Tuesday after the company reported fourth-quarter results that missed on revenue expectations and announced more artificial intelligence investments. Earnings per share for the Google parent company beat analysts' estimates by two cents. Here are other numbers Wall Street was watching:

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.