Overall, Facebook senior executives and board members have sold only 43 million of their own shares at a value of $1.5 billion, representing about 4 per cent of Facebook's shares outstanding.
Most of that was the result of a sale by Mark Zuckerberg, Facebook's chief executive, who sold $1.1 billion worth of stock at the IPO, almost all of which went to pay a tax bill. Additionally, Peter Thiel, early investor and board member, sold $1 billion worth of shares in August, with all of those funds allocated to his various venture capital firms.
But Mr Breyer's sales, which were the largest sold by a Facebook executive or director for individual gain, have garnered less attention.
Mr Breyer held 11.7 million shares at the time of the IPO, representing his personal investment in the company. He sold 3.3 million shares at the IPO for $127 million, then 3.5 million shares in October for $81 million, totaling $208 million.
He sold an additional 54 million shares at the IPO on behalf of Accel, a venture capital firm where he is a partner, netting Accel $2 billion, though Mr Breyer benefited personally from that sale as well.
After Facebook's IPO, Mr Breyer received several additional allocations of Facebook shares from Accel, meaning his personal share holdings in Facebook are roughly equal to the amount he held at the time of the IPO.
Mr Breyer did not respond to requests for comment.
Two other board members, Marc Andreessen, a partner at venture firm Andreessen Horowitz, and Donald Graham, the chief executive of The Washington Post, also sold parts of their personal stakes. Facebook said in an earlier filing that both directors intended to sell stock to cover tax liabilities.
Directors Reed Hastings, chief executive of Netflix, and Erskine Bowles, Democratic political adviser, have not sold any shares.
Among executives, Sheryl Sandberg, chief operating officer, has sold the most shares after Mr Zuckerberg, nearly $56 million worth, or about 5 per cent of the shares she held at the time of the IPO.
"The fact that they're largely retaining most of their original holdings in the company is the most important signal," Mr Yoffie said.
Facebook shares, which fell to less than $18 in September, have since rebounded, to $31.50 by midday on Friday. They listed at $38.
Additional reporting by Arash Massoudi in New York