Alphabet became the world's most valuable company after its 2015 corporate reorganization created a parent holding company.
Google announced Alphabet in August 2015, and the new structure took effect later that year. Alphabet became the parent company, while Google became its largest subsidiary, containing businesses such as Search, YouTube, and Android.
The reorganization separated Google's core internet products from experimental or specialized projects, including life sciences and investment activities. It also gave individual businesses greater operational independence and made their financial performance easier to report.
Alphabet briefly overtook Apple in market capitalization in February 2016 after reporting strong quarterly results. The ranking later changed repeatedly as technology share prices moved, so the historical superlative refers to that specific post-reorganization period.