The master of the revels is the film’s protagonist and unrepentant narrator, Jordan Belfort (Leonardo DiCaprio), upon whose self-aggrandising memoir the film is based. In his early 20s he joins a major stockbroking firm, but his coked-up mentor (Matthew McConaughey) has barely finished his introductory pep-talk—“Move your money from your client’s pocket into your pocket”—before Black Monday comes around and Belfort is laid off. When he can’t find another job on Wall Street, he resorts to selling penny stock from a boiler room in Long Island. He develops such a taste for aggressive and disingenuous cold-calling that he sets up his own company, Stratton Oakmont. His staff consists of a crack-smoking furniture salesman (Jonah Hill) and the various drop-outs he knows from school. Everyone is willing to follow the scripts he gives them, and they are just as willing to ignore his various illegal practices. Soon Stratton Oakmont is raking in millions—as well as attracting the attention of a doggedly disapproving FBI agent (Kyle Chandler).

Mr Scorsese is less disapproving. Having last made a children’s film, “Hugo”, perhaps he was in the mood for some swaggering, testosterone-drenched, adult-oriented entertainment. Whatever the reason, “The Wolf of Wall Street” is his most exuberant and overtly comic film: a frequently hilarious, manically energetic cavalcade of drug cocktails, naked blondes, helicopter crash-landings, and obscene spending sprees. It isn’t just studded with wild parties; the whole film is a wild party.

Still, the rowdiest parties are also the most tiring. “The Wolf of Wall Street” is, essentially, a string of hair-raising anecdotes, and while all of them are funny, outrageous and masterfully told, very few of them advance the plot or deepen the characterisation, so they become exhausting. It takes about half an hour for the hard-working Dr Jekyll to mutate into a hedonistic Mr Hyde, and from then on the film just keeps charging from one orgy to the next until the inevitable day when the FBI agent makes his move. It’s a wisp of a narrative, given the three-hour running time—Mr Scorsese’s longest ever.

Anyone who’s seen “Raging Bull” or “Goodfellas” will be waiting for the film to dig beneath the surface of the alpha-male anti-hero, and expose the self-loathing that makes him so reliant on drugs, prostitutes and designer suits. But the screenplay (by Terence Winter) is too carried away by the bacchanalian bad behaviour to concern itself with Belfort’s psyche. Instead, it presents him much as he’d present himself, and leaves the moralising to the viewer.

Why is “The Wolf of Wall Street” so soft on Belfort? Maybe it’s because Mr Scorsese, too, was a New Yorker from an unglamorous background who barged into the big time with motormouthed assurance before developing a severe cocaine addiction. When Belfort is shown handing out scripts to his employees, and pumping them up with inspirational speeches, he could be a film director himself: the uninhibited, live-wire Mr DiCaprio sometimes even looks and sounds like a younger Mr Scorsese. But whatever the similarities between Mr Scorsese and Belfort, the latter was still nothing more than a dissolute swindler—and that’s about all the film has to say on the matter. Still, it is possible to enjoy the rip-roaring party Mr Scorsese has thrown him without feeling that he is interesting enough to deserve it.