This summer, analysts were predicting that Harold Hamm could lose half of his $20 billion fortune in his divorce. Since then, Hamm's fortune has indeed been cut in half. But the reason is oil prices, not his divorce. Since the end of August, the CEO and founder of oil-company Continental Resources has seen the value of his shares in the company fall from $20 billion in late August to just over $10 billion on Friday. We don't know what other major assets or debts he has, or how leveraged he might be, but it's safe to say that Hamm's paper fortune from Continental has been cut in half in just three months. The $10 billion wealth-cut comes at the same time as his costly divorce ruling. Last month, a judge ruled that Hamm has to pay his ex-wife, Sue Ann, nearly $1 billion for their divorce . As part of the ruling, the judge has placed a lien on 20 million shares in Continental stock. Sue Ann's attorney has said she may appeal for more money.

Read More Jolie takes aim at 'mansion tax' Of course, Hamm is still rich. Even if he's down to his last $8 billion or $10 billion, he'll still be able to live the life to which he's grown accustomed.

But Hamm's sudden wealth loss shows that the new age of High-Beta Wealth-where massive paper fortunes can be created and destroyed overnight-isn't confined just to tech and financial companies. Even oil, one of America's oldest and most stable sources of dynastic wealth, has become more volatile recently.

Read More 400 top-earners in US made $106B in 2010 Hamm's rags-to-riches story has become legend. The 63-year-old oilman was one of 13 children born to Oklahoma sharecroppers. He took a job pumping gas after high school, then started cleaning oil tanks. He started a drilling company, and with a $1,000 loan eventually founded Continental. The company discovered the Cedar Hills Field in North Dakota in 1995 and went on to become one of the country's largest onshore oil companies. Hamm's rise from poverty may make it easier for him to weather the blows to his fortune. When talking about retirement, he once said: "I tried retirement once, but lasted six months because I feared, and I still do, that I'll fall back to that level of poverty. You really can't escape it." Read More States with the most super-rich residents