Alphabet, the new holding company for Google and its various sister companies, has seen shares jump to their highest-ever level in after-hours trading following news of its strength in mobile search results and the introduction of a share buyback scheme.

The companys Q3 results beat Wall Streets profit forecasts, sending stocks skyrocketing thanks to the solid progress the firm has made in building mobile and video advertising revenues. The results, along with the unexpected news of the buyback, have been welcomed by investors who are now betting on further growth for the company.

“Our Q3 results show the strength of Googles business, particularly in mobile search,” said Ruth Porat, CFO of Alphabet and Google. “With six products now having more than 1bn users globally, were excited about the opportunities ahead of Google, and across Alphabet.”

Alphabet brought in $18.7bn (£12.1bn) in revenues for the quarter, primarily through Googles advertising, a 13 per cent increase year-on-year. GAAP operating income sat at $4.7bn, up 25 per cent on this time last year.

The results may prove decisive as Google manages the transition from desktop to mobile, where it has traditionally earned lower revenues from advertising, and fights off competition from Facebook, Apple and others. However, with search traffic on mobile phones surpassing desktop traffic worldwide, Googles resulting high revenues will be a boost of confidence for the company and its shareholders.

Google accounts for 30 per cent of digital ad spending worldwide so far this year, with its closest competitor Facebook at 9.6 per cent, according to eMarketer. When it comes to search ad revenues, Google is even more dominant, with 52 per cent of the market and predicted annual revenues of $42.7bn.

“15 years to the day since Google began monetising its search enginge, these results highlight how far the company has come,” said John McNulty, head of global marketing at Marin Software. “With revenues up, new partnerships announced and recent product launches, it appears the company has no signs of slowing down. But questions are starting to rise around Googles future and its plans for advertisers.

“In the fight for advertisers wallets, Larry Page needs to fend off the mounting challenge from social platforms, with mobile a key battleground. As todays results prove, advertisers are not fatigued with Google even after 15 years. But to stay attractive to marketers, the company must continue to help react to changes in consumer behaviour.”