Amazon's share price opened nine per cent up, while Google's stock soared 11.7 per cent and Microsoft's shares rose 10.2 per cent.
Results posted yesterday showed online retail giant Amazon's net sales rose 23 per cent to $25.4bn (£16.5bn) in the three months to the end of September, while net income hit $79bn.
Meanwhile, Google's revenue increased 13 per cent to $18.7bn in the same period.
Revenue from Google - now known as Alphabet - rose 16 per cent to $13.1bn for its websites division, while paid clicks jumped by 23 per cent.
Alphabet announced the group's first stock buyback yesterday, worth $5.1bn, which marked the latest step in its transition to a new management and financial structure.
Microsoft also posted encouraging results, with revenue of $20.4bn in the third quarter. The company's cloud computing sales offset declining sales elsewhere, with eight per cent sales growth pushing revenues to $5.9bn.
On a lighter note, Google's $5bn buyback was actually exactly $5,099,019,513.59. Why? Well, because 5.09901951359 is the square root of 26, the number of letters in the alphabet.