The pockets of the rich are undoubtedly feeling a little lighter these days. The number of billionaires in the world fell by nearly a third to 793 with an average net worth of $3 billion, down 23 percent in 12 months, according to Forbes' annual billionaires list released this month.

Approximately 4.4 percent of the billionaires are American real estate players.The net worth of many of these individuals has substantially decreased over the past year. For starters, industry giant Sam Zell's net worth plummeted by 50 percent; Stephen Ross of the Related Cos. took a 29 percent hit; and the once unstoppable Donald Trump suffered a 46.7 decline.

These losses don't come as a surprise. "Big guys make the biggest bets so naturally they are going to take the biggest hits," says Michael Lynd Jr., vice president of investments for the San Antonio-based management firm The Lynd Co. "There isn't a real estate guy in the country?unless he is lying to you?that hasn't experienced a substantial value hit to his portfolio. I'd estimate real estate values are down anywhere from 20 percent to 30 percent, potentially more depending on the asset class. In the multifamily sector, job loss is putting downward pressure on occupancies and rents, and it's tougher to generate NOI."

Somewhat miraculously, a handful of real estate tycoons managed to break even or increase their net worth. Paul Milstein of Milstein Properties, which owns apartments and offices throughout New York City, retained his $4.5 billion net worth. Another Big Apple titan, Richard LeFrak of the LeFrak Organization, saw his worth climb 33 percent, while Ted Lerner, founder of Lerner Enterprises, had a 28 percent uptick.

Multifamily execs are confident that other real estate investors' pockets will get heavier, too. "It's just a matter of time," says Chris Finlay, managing principal of Oakton, Va.-based management firm Mission Residential. "I expect people who showed losses during the last year will probably see values come back as the market recovers, which it inevitably will." So don't feel too badly for Trump and his buddies.