Everything about Mikhail Prokhorov is large -- his height (6-foot-7), his appetite for spending, and his bank account (a reputed $9.5 billion).

He has offered a bid of $750 million for a French castle, then changed his mind and forfeited a $50 million deposit. A video is circulating around YouTube of him doing a back flip on a jet ski. And he is one of the best in his country at kickboxing.

The Russian billionaire recently barged onto the American stage with his offer to buy the New Jersey Nets of the National Basketball Association and build an arena for them in Brooklyn. This would entail a $200 million investment, a mere afterthought for a man ranked by Forbes as the 40th richest man in the world.

In Russia, Prokhorov became known as a sort of George Steinbrenner, pouring millions of dollars and a half-dozen NBA stars into his men's and women's CSKA teams, which soon began to dominate.

Born May 3, 1965, Prokhorov graduated from the Moscow Finance Institute ready to make his mark in the emerging and chaotic landscape of post-Soviet Russia. His first coup was convincing several Russian lending institutions to bankroll his bid for Norilsk Nickel, which became the world's largest producer of that mineral under his direction. At the time he assumed control of Norilsk, he was only 28.

From there, Prokhorov moved into gold and then nanotechnology, priming the pump for extensive research in hydrogen fuel cells.In June of 2007, he was appointed to the 15-member Government council for Nanotechnology.

Prokhorov plays the financial game as if he were seated at a blackjack table in LAs Vegas, flashing an innate skill at taking an investment as far as it will go, then cashing in to try something else.

In a few other cases, these changes have been beyond his control. He stepped down from his position as CEO of Norilsk Nickel, for instance, after he was accused of hiring prostitutes for guests at a Christmas party in the Alps. He was never charged with a crime.

According to David Vanterpool, who coached CSKA under Prokhorov: “A lot of what I read, people are equating him to a James Bond character — a lot of mystery, a lot of things about him,” Vanterpool said with a laugh. “But he’s a guy who enjoys his life and has been blessed with a lot of wealth and intelligence.

“And he’s a traditional fan who likes a good game and presentation. He’s given a lot of reasons for buying, but I think his primary motivation really is to see the sport grow in his own country, and put the sport on the map there. He’s not egotistical about it. I mean, CSKA was a European powerhouse, but it was never about him. I’ve seen NBA executives sit next to him at our games and they didn’t even know who he was.”

Prokhorov's bid for the Nets still has to be approved by the NBA's board of governors.