Last month, Google's founders Larry Page and Sergey Brin announced they would step back from Alphabet, which they have run since restructuring Google in 2015. Google - which includes its search engine, Android operating system and online advertising network - is now listed as one subsidiary of the Alphabet parent, which also includes driverless car division Waymo and a string of other ventures. However, Google continues to make up the vast majority of Alphabet's revenues. Mr Page and Mr Brin, who founded the company while studying computer science at Stanford University in 1998, made way for Google chief executive Sundar Pichai, a move that analysts said could bring more financial discipline to the Alphabet group. The share price rise also comes despite the company facing internal turmoil. Employees have become more vocally critical of the company, which has faced allegations of sacking workers who spoke out about sexual harassment and discrimination.