(FORTUNE Small Business) – To Darryll Bolduc, the transition was swift and brutal: One moment he was a high-flying Wall Street trader, and the next he was spurned as a lowly Wall Street traitor. Bolduc's crime? He told his superiors about what he believed were deceptive accounting practices at Charlotte-based NationsBank, where he worked as a foreign-bond portfolio manager. This was 1995, eons before strong-minded rebels at Enron and WorldCom would be praised for speaking truth to power. Not only was Bolduc fired, but he says he had trouble finding a lawyer in a town where connections between banks and lawyers run deep. "I was blackballed," says Bolduc, 43, who sued NationsBank, which denied wrongdoing but settled the case for $600,000 in 1996. "I had to do a lot of my own legal research and ended up getting hooked on the law."

Nearly a decade later the pioneering whistleblower, armed with a law degree, has opened a practice specializing in--what else?--cases brought by corporate whistleblowers involving securities and employment law. He's busy, thanks to the Sarbanes-Oxley Act, the 2002 law that imposed stiffer penalties for corporate fraud and has triggered lawsuits. "There's a lot of litigation going on right now in the financial services industry," says Bolduc. He adds, "My motivation is not revenge. I just want to build a practice."

If his ambitions are grand--he expects this year's projected revenues of $500,000 to rise to at least $3 million by 2007-- Bolduc's business plan is modest. He eschews full-time secretaries and paralegals. He rents a $2,000-per-month office, subcontracting support staff (average cost: $30 an hour) to handle his 20-case load. To lure clients, Bolduc--who pays himself a $100,000 annual salary--uses what he calls a "mixed contingency" fee structure, which combines an hourly rate and a percentage of any winnings. The arrangement places some of the financial risk on clients. "Doing it this way really keeps the client involved," he says. And, he hopes, keeps them whistling loud and clear.