Alphabet Inc. is an American multinational conglomerate headquartered in Mountain View, California. It was created through a corporate restructuring of Google on October 2, 2015, and became the parent company of Google and several former Google subsidiaries. The two founders of Google assumed executive roles in the new company, with Larry Page serving as CEO and Sergey Brin as president.Alphabet's portfolio encompasses several industries, including technology, life sciences, investment capital, and research. Some of its subsidiaries include Google, Calico, Chronicle, GV, CapitalG, Verily, Waymo, X, Loon and Google Fiber. Some of the subsidiaries of Alphabet have altered their names since leaving Google and becoming part of the new parent company—Google Ventures becoming GV, Google Life Sciences becoming Verily and Google X becoming just X. Following the restructuring, Page became CEO of Alphabet and Sundar Pichai took his position as CEO of Google. Shares of Google's stock have been converted into Alphabet stock, which trade under Google's former ticker symbols of "GOOG" and "GOOGL". As of 2018, Alphabet is ranked No. 22 on the Fortune 500 rankings of the largest United States corporations by total revenue.The establishment of Alphabet was prompted by a desire to make the core Google Internet services business "cleaner and more accountable" while allowing greater autonomy to group companies that operate in businesses other than Internet services.