Nasdaq was down two per cent at the opening bell, whilst European tech stocks fell 1.8 per cent to lead sectoral losses.
It comes after Alphabet said third-quarter revenue grew six per cent to $69.1bn, raising concerns about slowing growth across digital advertising and ecommerce.
YouTube was a big source of weakness for the second quarter in a row, with the division’s revenues of $7.07bn.
Meanwhile, Microsoft warned there would be a significant slowdown in its cloud computing business in the coming months, scuppering hopes that this could save the dwindling PC market.
It said higher energy costs from running giant cloud data centres were cutting into profit margins, adding $800m to costs this year.
Both Alphabet and Microsoft saw their shares tumble a further seven per cent in early morning trade, adding to their respective 33 per cent and 30 per cent plunge in the year to date.
However, lead equity analyst at Hargreaves Lansdown Sophie Lund-Yates backed Alphabet’s resilience.
“Plenty of tech companies rely on advertising revenue and the changing economic temperature saw Snap’s shares enter a landslide earlier in the month. The reason Alphabet isn’t following suit to the same degree is because it’s utterly indispensable,” she said.
“Demand may ebb and flow, but it will never turn off completely, and that’s reflected in a pretty remarkable share price performance over the last month. Google isn’t a trend that might dissipate, it’s a fundamental daily activity for swathes of the globe’s population”.