“It’s all about the respect he had for his mother,” said Elizabeth Saltzman, international social editor of Vanity Fair, who met Mr. Nevo on the New York social scene in the 1980s (the second time she met him she shared a helicopter with him to the Hamptons). “His mother was everything. I think there’s a huge mama complex, of trying to make her proud.”

With the inheritance  which one business associate of Mr. Nevo’s, who spoke anonymously because his conversations with him were meant to be confidential, pegged at around $10 million  Mr. Nevo set about investing and networking. He opened trading accounts at Goldman Sachs and Morgan Stanley, as well as Allen & Company, which eventually won him an invitation to Sun Valley, the place that became the locus for so many of his relationships, including those with Mr. Parsons and Lachlan Murdoch. Through diligence and hard work, the right contacts and a lot of the right trades during the dot-com bubble of the late 1990s, he turned his inheritance into a sizable fortune.

Mr. Mack said: “He took the money his family left him and he really created this media, trading empire. At Credit Suisse we did a lot of trading business with him, either outright or with derivatives.”

How much money he made is really anyone’s guess. When Mr. Nevo began appearing a few years ago on certain lists, like Vanity Fair’s New Establishment list, Forbes tried to gauge Mr. Nevo’s wealth to see if he belonged on the magazine’s list of billionaires, but ultimately gave up trying. Mr. Nevo owns homes in Malibu, Calif.; the Los Angeles-area neighborhood of Brentwood; the TriBeCa neighborhood of New York; London; and two homes in Tel Aviv, including his modest childhood home outside the city, which sits empty. In addition, he and Ms. Zhang recently bought a home in Beijing.

“Vivi is a very hard worker, and we’d begin chatting about the markets in the early morning, and then we’d talk late in the afternoon,” said Bob Packer, who ran Goldman Sachs’s institutional equities unit in San Francisco and handled many of Mr. Nevo’s trades. “He loved working with the markets. He’s just a really affable, wonderful, loyal guy.”

In the case of Time Warner, his relationship with the company and its executives began in the early to mid-1990s, when he established a relationship with Gerald M. Levin, then chief executive.

“It was in a social context,” Mr. Levin said, trying to recall how he met Mr. Nevo. “I would go to every major fight that HBO had in Las Vegas. It was either at the fights in Las Vegas or at some movie premiere. No, I think it was in Vegas.”