In these uncertain times, you hear a lot of sad stories about how average Americans are afraid of losing their jobs or drowning in debt. But what about the suffering of the young and wealthy? Who's keeping an eye on them? Fear not: In its latest "Wealth in America 2008" survey, Northern Trust has found that "young millionaires are best positioned to survive market volatility." Whew! The findings do say something about how the members of generation X's upper crust are building their fortunes. They're more sophisticated investors than the baby boomers who preceded them, with bigger appetites for risk. Some 23 percent of their assets go to alternative investments like hedge funds, private equity, or real estate, compared with 14 percent for boomers and 10 percent for the so-called silent generation (ages 62-77) who preceded them. Gen X-ers are also less likely to get scared out of risky investments even with markets as volatile as they are right now because they're still working and earning enough from their day jobs to give their investments a longer horizon than their older counterparts.