Amazon shares fell 4% in Frankfurt on Friday a day after the retailer's results showed weakness in its cloud computing unit and it forecast and lower-than-expected first-quarter revenue and profit.

The search giant said it will spend a staggering $75 billion this year as the AI arms race heats up. Investors may have concerns about whether it will pay off. Shares in Google’s parent company, Alphabet (Nasdaq: GOOG),

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.