Some call him a visionary. Others, no more than a confidence man. In fact, Kavanaugh is Los Angeles' answer to Gordon Gekko, the corporate raider at the center of Wall Street, one of his favorite movies. Like Gekko, Kavanaugh is quick-witted and relentless, and believes devoutly in the primacy of making money. His four biggest deals linking Hollywood and "my guys," as he likes to call hedge funds and banks, have yielded a commitment of more than $500 million-each. The deals have helped fund films that range from popcorn fare (the action fantasy Ghost Rider) to literary adaptations (the upcoming Atonement, from the award-winning novel by Ian McEwan).

Now, Mulholland Drive will take Kavanaugh to another level. He has always collected fees for putting investors together with studios, like a handful of other middlemen in town who make their money no matter how the movies perform. But this deal will give Kavanaugh both fees and an ownership stake in the movies themselves—meaning he will share in the risks and rewards (proceeds from worldwide theater tickets, pay-per-view deals, DVDs, and merchandise). Add Kavanaugh's youth and lack of an M.B.A., and it's no surprise that the onetime aspiring rock guitarist has become the most controversial figure in the secretive world of Hollywood finance.

"You're going to hear tons of criticism," barks Harvey Weinstein, a movie mogul who is working on several deals with Kavanaugh. "Dismiss it for the absolute envious nonsensical gossip that it is. Any investment banker who says anything negative about Ryan—as I've heard a few of them say—is jealous." Weinstein says such static is driven by one simple fact: Kavanaugh is making money that used to go into other people's pockets. "I've heard, 'He's the devil. You can't do business with him.' Then you hang out with Ryan, and he's smarter than all five of the guys who told me he's the Antichrist put together."

Kavanaugh's critics charge that he embraces a certain plasticity of truth—often stressing the possible over the probable. In Hollywood, this kind of salesmanship is admired. On Wall Street, however, it can raise eyebrows. Some allege that he will say almost anything to close a deal, making promises he may not be able to keep.

As evidence, they point to Kavanaugh's first major enterprise, a venture capital firm he launched at age 22. Four years later, he shuttered it. The firm's failures resulted in five lawsuits, one of which yielded a $7.7 million judgment in favor of an investor (who is still trying to collect).

"I have nothing to hide," Kavanaugh says one night over a late sushi dinner. "I've made money and lost money." An hour-a-day treadmill runner who tries to never touch carbs, he eats four dinners a week at Nobu Malibu, not far from the three-bedroom oceanfront beach house he rents. He chopsticks a piece of toro tartare—"comfort food" to his mouth and adds, "When I was 22, I had a multimillion-dollar house and two Ferraris, and I was flying private. At 26, I was like, 'How am I going to pay my rent?' But it's the crash you learn from."

After his V.C. fund sank, "Ryan had no credibility," says Mark Canton, the former production chief of Warner Bros. and chairman of Columbia Tristar who was one of Kavanaugh's investors. "He's gained credibility rather quickly."

Canton declines to say exactly how he fared in Kavanaugh's fund, noting that some investments are still pending. But its poor performance, he says, "didn't cause me to lose confidence in the bigger picture.

"Ryan's a finisher. That's what we like. He's really good at marketing his product. And his product is him."

The V.C. fund, however, isn't the only strike against Kavanaugh. There's also Virtual Studios, a partnership he brokered in 2005 between Warner Bros. and Stark Investments, a Wisconsin-based hedge fund, that until this spring had released nothing but duds. Virtual invested $537 million in seven Warner Bros. movies. The most expensive one, the $160 million remake Poseidon, was one of last year's most embarrassing flops; three others released in 2006 were box office disappointments.