Mark Zuckerberg made $3.5 billion last month (November)

Yes, you heard right. $3.5 billion in just one month. Facebook's stock shot up from $21.08 a share on the first day of trading in November to $28 a share at the end of the day Friday, its highest price since July. Zuckerberg, who owns about 504 million shares of Facebook stock, gained about $3.48 billion as a result...
When Facebook first went public at $38 a share in May, Zuckerberg’s shares were worth $19.1 billion. In the following months, the stock dropped to less than half that IPO price to $17.55 in late August, pushing Zuckerberg’s net worth down to $8.84 billion.

Since then, Facebook’s stock has recovered in fits and starts and so has Zuckerberg’s wealth. November proved to be by far the most robust growth month for the stock to date, thanks to two big factors. First, the company had a strong earnings report in late October, which showed that Facebook was making progress in monetizing mobile. Secondly, the second and largest lockup period for stocks held by employees finally expired in the middle of November, which was something investors had been dreading for months and arguably held down the stock price.

As of last Friday, Zuckerberg’s net worth was $14.1 billion and will likely only continue to grow in December.