Looking back at life on the buy side

A buysider's fall from grace

For Turney Duff, life on Wall Street's buy side was full of excess, whether it was money, alcohol, drugs or sex. But after 15 years, he called it quits.

"I was constantly trying to top myself ... A private jet to Vegas is cool, but a private jet with hookers and eight-balls of cocaine is much cooler. And the next time you've got to bungee jump on your way to Vegas, so you're just continually trying to top yourself and there's no winning in that," Duff said.

The former Galleon Group trader worked under the now infamous Raj Rajaratnam, taking calls from a source he called "Mr. Whisper."

(Read more: Time to stop hating on Wall Street: Turney Duff)

"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.

(Read more: Advice for young Wall Street: Turney Duff)

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