Alphabet said on Tuesday it will spend $75 billion on its AI buildout this year, 29% more than Wall Street expected, and investors signaled disappointment at a missed cloud revenue target and began showing impatience over profitability.

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

Excluding traffic acquisition costs, that figure was $81.6bn, missing Wall Street estimates in a Bloomberg poll of $82.8bn. Net income rose 28 per cent to $26.5bn. Alphabet shares dropped more than 6 per cent in after-hours trading.