In line with his pledge to give away 99 percent of his shares to philanthropy and being cautious to not sell or give away more than USD 1billion in Facebook stock per year till 2018, Mark Zuckerberg recently sold his shares in Facebook worth USD 95 million.

According to regulatory filings quoted by Forbes, the Chan Zuckerberg Foundation and CZI Holdings LLC, the two entities that Zuckerberg and his wife Priscilla Chan created for their philanthropy and public advocacy last year, sold the shares between November 17 and November 18.

The sale follows USD 190 million in Facebook stock sold by the same entities in October and another USD 190 million sold in September.

In December 2015, Zuckerburg and Chan had first announced to give away 99 per cent of their company's stake, which was then worth about USD 45 billion, in a letter to their baby to make the world a better place, for philanthropic, public advocacy and other activities for the public good over their lifetime. Some of the funds will go into for profit companies that fit with the couple's goals.

The more he gave, the more he made

Following these sales, Forbes estimates Zuckerberg's net worth at USD 52 billion. His net worth has increased over the past year despite the stock sales as a result of the rise in Facebook's stock price.

Zuckerberg is currently the fourth richest person in the world, according to Forbes estimates.

Chan and Zuckerberg announced one big goal in September, when they pledged to spend USD 3 billion over the next decade to fight disease. If we can develop new tools, we can empower scientists all around the world to make much faster progress and breakthroughs, Zuckerberg had said.