NEW YORK (MainStreet) — It used to be enough to proclaim a goal of being a millionaire by age 40. Now that seems to indicate some degree of a lack of ambition. Billionaire? Now you’re talking. But if you are aiming for the rare air of the “We’re off to St. Bart’s to ring in the New Year” crowd, the clock is ticking. While the average age of your typical billionaire is 63 years old -- over half are older than 65 -- most billionaires became ten-figure rich by their late 40s.

The latest survey of ultra high net worth individuals by Wealth-X and UBS finds that between July 2013 and June 2014, the billionaire population grew by 7% -- reaching an all-time high of 2,325. Most are self-made (83%) who own their own privately-held businesses (63%).

Their combined wealth tops $7.3 trillion, which the report says “is higher than the market capitalization of all the companies that make up the Dow Jones Industrial Average.”

And since most of the ultra-rich didn’t inherit their fortunes, you might think wise investments put them over the top. In fact, their portfolios underperformed the global S&P1200 equity index over the one-year time frame. Not to fret though, these tycoons are in defensive mode: on average 19% of billionaire wealth is held in cash.

Yet the uber-rich are diversified. About 5% hold real estate and luxury assets; let’s face it, one residence is just not practical when you’re globe-trotting. And one in 30 billionaires owns a sports team or a racehorse. Not to mention the requisite yachts, aircraft, cars and art.

By and large, the billionaire society is still a man’s club, but that is changing.

“With 89% of male billionaires being married, we can expect a substantial amount of wealth transfer to their immediate family members in the coming years,” the report notes. “However, we predict that billionaires who have made all, or most, of their fortunes will remain the most common type of billionaires.”

While high-tech moguls like Bill Gates, Paul Allen, Mark Zuckerburg and Larry Page fuel dreams of coding your way to copious cash, most billionaires (19%) have made their money in the finance, banking and investment industry. Technology titans represent a mere 4% of the world’s current crop of billionaires, though that is expected to grow significantly in the coming years, according to Wealth-X.

More than one third (35%) of the world’s richest rich don’t hold a degree, and some even dropped out of high school. But the top five schools that can boast of the most billionaire alumni may surprise you. Of course, Harvard (ranked #2) and Yale (#3) are near the top, followed by USC (#4) and Princeton (#5), though the school leading the list is the University of Pennsylvania.

Coincidentally or not, UPenn this week also won the honors as Playboy’s top ranking party school in the nation.

--Written by Hal M. Bundrick for MainStreet