America's 400 wealthiest people hold fortune $1.37 trillion in total

The combined worth of the 400 wealthiest citizens in America rose to $1.37 trillion this year, an 8 percent increase over 2009, though still shy of the $1.57 trillion total from 2008, according to Forbes' annual rankings, released Wednesday night.

Microsoft founder Bill Gates, who topped the list for the 17th year in a row, saw his wealth grow to $54 billion, up from $50 billion last year. Warren Buffett trailed closely with $45 billion, a full $5 billion more than he had the year before, NJ.com says.

The biggest gainer in the pack of richest U.S. techies was the wonderboy Mark Zuckerberg, the 26-year-old founder of social network Facebook. Zuckerberg's fortune more than tripled in the past year, from $2 billion last year to $6.9 billion this year.

Private-equity investments in Facebook over the past year put the value of the company at $23 billion. Revenue is expected to top $2 billion this year. Zuckerberg continues to live in a rented house in Palo Alto, Calif, Forbes informs.