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Google shares soared to an all-time on Friday with the tech giant adding about $60bn to its market value.

Google's shares closed 16.26% up as investors cheered profit figures that showed strong advertising growth on mobiles and its YouTube arm.

The rise took the company's market size to well above $400bn (£256bn), second only to Apple, valued at $745bn.

It means that Google co-founders Larry Page and Sergey Brin each made a paper profit of about $4bn in just one day.

On Thursday, after trading had closed, Google reported that second-quarter net income was $3.93bn in the three months to end-June, up from $3.35bn for the quarter a year earlier.

The results ended six consecutive quarters in which Google's earnings fell short of analysts' targets

Finance chief Ruth Porat highlighted the growth in mobile advertising and time people are spending streaming video's on YouTube.

She said YouTube had more than one billion users and that the number of people in the key 18-49 age group who watch its videos on mobile devices was greater than the number watching cable television.

Reuters reported that at least 27 broking firms raised their price targets for Google shares, with one predicting that the stock could rise as high as $800.

As the market opened on Friday, Google added an instant $50bn as the shares jumped. The stock eventually closed $97.84 higher at $699.62.

The rise helped the tech-rich Nasdaq index, on which Google is listed, close at a record high for the second consecutive session on Friday, ending up more than 0.9%.

Deutsche Bank issued a research note on the profit figures called "Dawn of a New Era?" - adding that it "feels like it".