A Generation X cautionary tale about greed and impatience, "Boiler Room" is a sharp-edged, adrenaline-driven movie that takes place in the eat-or-be-eaten world of crooked stock trading.

Populated by 25-year-old, overnight millionaires who wear their testosterone on the sleeves of their tailored Armani suits, this is an imposing, vigorous and pulsating picture that could have been mighty and portentous if writer-director Ben Younger hadn't cribbed half the script from "Wall Street" and "Glengarry Glen Ross."

Giovanni Ribisi ("The Mod Squad") plays an unscrupulous college dropout looking to make a quick buck with an underground casino he runs from his rented row house. But he starts seeing much bigger dollar signs when a newly-rich (and Ferrari-driving) acquaintance recruits him to cold-call moneyed suckers and pitch them investments for his suspicious brokerage startup.

Far from being a Financial District firm, the joint is hidden in a nondescript office park off the Long Island turnpike. Ribisi goes in for an interview and finds himself subjected to Ben Affleck's raving rehash of Alec Baldwin's "Always Be Closing" monologue from "Glengarry." He's pretty good at it, too, barking "They say money can't buy you happiness? Look at the smile on my face!"

Affleck should specialize in these surgical strike roles. This is the best he's been in anything since his two-scene part as a conceited actor in "Shakespeare In Love."

Anyway, Ribisi becomes a Y2K clone of Charlie Sheen's Bud Fox character from "Wall Street" -- a deceitful junk stock hawker whose conscience rattles in the dark recesses of his soul while he buddies up to the firm's big shots and begins to learn the dirty secrets behind their success. And like Bud Fox, it's not long before the FBI is knocking on his door.

Younger is a very strong director and he gives this picture an intense potency, personifying how power and money can corrupt through Ribisi's great performance as a piranha-in-training. In a snazzy bit of casting, Younger staffs the fly-by-night firm with arrogant bruiser types that in most other movies would be playing hit men, mob enforcers or serial killers. The pumped-up brokers are actors like Vin Diesel (an escaped mass-murderer in this week's "Pitch Black"), Nicky Katt (one of the rapists in "A Time To Kill") and Scott Caan (as the son of James Cann, tough guy roles are in his DNA).

The rookie writer-director does a precision job with his movie's moods, too, building a pressure-cooker atmosphere in the office and off-setting it with occasional, entertaining asides that demonstrate the effect this air has on his hero. In the best scene in the movie, Ribisi gives a newspaper subscription salesman a lesson in the art of the pitch while eating his Shredded Wheat and Coca-Cola breakfast.

Another nice touch that adds to the film's relentless intensity: The soundtrack is almost entirely hardcore rap. The juxtaposition with the white (skin and collar) cast is an irony not lost on the audience, although it does help call attention to one of Younger's silly mistakes: Sexy, confident black actress Nia Long ("The Best Man") plays the pasty, dog-eyed Ribisi's love interest. Sorry, I'm just not buying her attraction to him.

On the other hand, Ribisi's tenuous relationship with his disapproving, district court judge dad (Ron Rifkin, "The Negotiator") is perfectly tinged with his desperation to earn his father's respect.

One more smart move: Younger chose one client (Taylor Nichols, "Metropolitan") to represent the everyday joes getting robbed blind by these guys. We get to watch his family self-destruct as the stock Ribisi sold him plummets 86 percent in a day.

The only complaint of any import I have about "Boiler Room" is its heavy structural dependence on "Glengarry" and "Wall Street." This is a problem that's hard to imagine a way around, since the kind of ruthless young brokers portrayed in this film probably really do look to these movies as part of their dogma and worship at the altars to Gordon Gekko and Ricky Roma.

If only there was a way past that paradox, "Boiler Room" would be great, because in spite of its flaws, the movie is an enticing portrayal of high finance as a contact sport, and it leaves a deep impression of irony (in retrospect, his illegal casino was a more honest business) and the pitfalls of unmitigated greed.