Google is the company to beat when it comes to internet search and online ad sales. The company has seen stock prices as high as $600 per share since the company went public.

News of one of Google’s most important executives leaving led to Google seeing its lowest stock prices of the year as shares fell as low as $435.78 in heavy trading according to Reuters. The executive that caused this drop is stock price is Sheryl Sandberg, who is reported to be the main executive responsible for Google’s advertising programs that account for the vast majority of Google’s financial gains.

Reuters quotes RBC Capital analyst Jordan Rohan saying, “Sandberg's departure is a significant loss for Google. It signals that the company has reached a level of scale and bureaucracy with which some early Google employees are uncomfortable."

Google’s top three executives, Sergey Brin, Larry Page, and Eric Schmidt are probably wishing they had included Sandberg in their 20-year pledge. Google’s loss is Facebook’s gain as Facebook announced it had snagged Sandberg to act as its new chief operations officer. Sandberg’s departure makes the first executive to leave Google since its IPO in 2004.

Sandeep Aggarwal, an analyst at Oppenheimer, told Reuters, “It is a significant move [Sandberg leaving]. This could be the start of others leaving.” Sandberg will manage sales, marketing, business development, human resources, public policy, privacy issues and communications for Facebook.