He sure knew how to play to his audience: "I'm a bit of a CNBC nerd. I follow CNBC like some people follow 'Star Trek.' My mom asked me what do I want for Christmas I told her, 'A Bob Pisani action figure!,'" referring to CNBC's reporter on the floor of the New York Stock Exchange.
(Hey, that's a good idea. Marketing department, are you reading this?!)
Later, he said he thought about going for Halloween as the "coolest dude in America"—Federal Reserve Chairman Ben Bernanke. But he's always had a hard time growing a beard. "So, I went as the next closest thing: A money-printing press!"
Tune in to CNBC's "Power Lunch" today from 1-2pm to see clips from Raj's performance at CNBC. Cindy will be on with reporter Kayla Tausche to discuss the pressing question, "Are Wall Street guys funny?" and more.
Mahal said having worked on Wall Street offers up A LOT of comedy material.
"There are a lot of stereotypes of Wall Street people, and I'm glad to say—most of them are true!" he said.
No business topic was safe: He did jokes on everything from being part of the 1 percent to Obamacare.
"That website takes forever! By the time I'm able to enroll in Obamacare, I'm going to be eligible for Medicare!" he said.
Of course, you have to wonder why a guy would give up a lucrative career in trading for a career that usually pays more in laughs than it does dollars.
"Sometimes in life, money isn't the only thing," he said (to the collective gasp of Wall Street). "I was burned out a bit and decided to take a hiatus—and this is where I ended up."
And, uh, what do his parents think about his decision?
"My parents have been very supportive … but probably not what they envisioned when they paid for Wharton," he said, adding that when he told his parents he'd be performing at CNBC, his dad said, "Ask them for a job!"
His competition includes all kinds of Wall Street types, from traders to investment bankers and financial advisors. Click here to watch some of the other contenders in the battle for "Funniest Person in Finance."
The winner will be announced at the finals on Nov. 13 at Gotham Comedy Club.
—By CNBC's Cindy Perman
Cindy Perman is the commentary editor for CNBC.com, as well as the author of the Pony Blog and the book, "New York Curiosities." Disclosure: She has performed stand-up comedy at Gotham Comedy Club. Follow her on Twitter @CindyPerman.
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Turns out, finance guys are pretty funny
The top 10 ways sharks and bankers are alike
Want a job on Wall Street? 'Let me sleep with your girlfriend'
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