A filing with American regulators on Wednesday revealed that Mark Zuckerberg’s stake in Facebook (FB) has climbed to nearly 30% since the company’s disastrous initial public offering last May, Agence France Presse reported. The CEO and co-founder now owns a total of 632.65 million shares of Facebook, compared to about 500 million shares this past fall. After the company’s stock fell to an all time low of $17.55 in September, Zuckerberg promised that he would not sell any of his shares for at least a year. Recent Securities and Exchange Commission filings show that Zuckerberg has continued to purchase stock since making that promise.