The cinematography in Baz Luhrmann’s new film version of "The Great Gatsby" portrays the Jazz Age as full of lavish excess and glitz probably not even dreamed of in 1922, the year F. Scott Fitzgerald’s story takes place.

Flaunting the wealth of Jay Gatsby is the movie’s focal point of extreme gluttony: Gatsby’s weekend parties feature more bling than Jay-Z. The source of his wealth, however, is somewhat mysterious: The phone rings constantly throughout the film, with calls identified only as “Chicago” or “Philadelphia.”

“He owned some drug-stores, a lot of drug-stores,” according to Gatsby’s lost love, Daisy. Connections to the man who fixed the 1919 World Series and bootleggers are alluded to.

PHOTOS: Mark Zuckerberg and Other Young Moguls

Could such a mysteriously wealthy person exist today, apart from fiction? Or would his wealth be outed as fast as Tom Buchanan could log on to Twitter?

It’s plausible, said Michael Rubin, author of "Beyond Paycheck to Paycheck: A Conversation About Income, Wealth, and the Steps in Between."

“You could start a company that’s not worth anything more than $100 and seven years later it’s worth $50 million, and only you and your shareholders know it,” Rubin said.

There’s no wealth tax in the United States, Rubin points out, so legally accumulating a great deal of wealth and keeping it relatively secret is not uncommon.

Warner Bros./Facebook

“There are plenty of millionaires amongst our midst that you would never know about,” he said.

Of course, once you start throwing Gatsby-esque parties, the more questions your neighbors might ask.

“Almost certainly you can be rich without people knowing where you got your money,” said Terrance Odean, professor of finance at the Haas School of Business at the University of California, Berkeley. “Real estate, an inheritance, art, the market .... As long as your social circle doesn't overlap too much with your vague source of wealth, you are probably fine. Many people consider it rude to ask. Of course, if a reporter pries some stories will fall apart fast than others. Thus it is helpful if you -- and your wealth -- come from another country.”

NEWS: Diamonds: What's With the Love Affair?

On the flip side, many people in the United States may flaunt wealth they don’t actually have.

“Some of those who lead a lavish lifestyle are actually in debt,” Rubin said. “Recent studies show that up to 60 percent of the people in this country live paycheck to paycheck. I think people often assume that a big house means you’re wealthy, but that’s not really the case at all. There’s some correlation, but it’s a loose one.”

Celebrities, of course, face closer financial scrutiny. In March, a website published private financial records of Jay-Z and Mel Gibson, Hillary Clinton, Beyonce, Paris Hilton and others. There’s even a term for it: doxxing.

Fitzgerald’s book draws a greater distinction between old money and new money. Not even Gatsby’s great wealth wins him entree into the lifestyle of the woman he lusts after.

"Her voice is full of money," he tells neighbor and narrator Nick Carraway.

While Gatsby’s finances seem tenuous, he never reaches financial ruin. The story, of course, still ends in tragedy.