The former Galleon Group trader worked under the now infamous Raj Rajaratnam, taking calls from a source he called "Mr. Whisper."
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"So I was at the Galleon Group and the phone rings and the person on the other end of the phone starts whispering ... and the guy says Jeffries is going to upgrade Amazon in six minutes, " Duff recalled. "So I got six minutes to decide, do I go and buy Amazon, and if I do, isn't that illegal? As the clock ticked by, I eventually bought 100,000 shares and six minutes later, boom, Amazon's upgraded and the stock's up $5 and I make a half million dollars in a few minutes," Duff said.
But while eventually making millions of dollars in minutes and getting seven-figure bonuses were thrilling, they weren't ultimately the highlights of his life, Duff said.
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He eventually gave up his extravagant, drug-fueled life, funded by his Wall Street winnings, in exchange for a more modest way to make a living: writing.
"The one thing that you'll hear constantly, more so on the buy side ... is you find out who your true friends are when you leave the business," Duff said. "I would say of the 100 percent of 'Wall Street friends,' 15 to 20 percent still exist."
—By CNBC's Althea Chang. Follow her on Twitter @altheadchang