For years, he refused to reveal even the slightest personal financial information. But Nader, who next weekend expects to become the Green Party's nominee for president, discussed the topic in interviews with The Baltimore Sun and Washington Post, detailing personal assets approaching $4 million.
Nader also disclosed financial information in a report filed with the Federal Election Commission.
A telephone message left at Nader's campaign office in Washington was not immediately returned.
The Sun reported that Nader earned more than $512,000 over the past 16 months, mostly in speaking fees. The newspaper also said Nader's personal holdings are conservatively valued at more than $3.9 million, including a stock portfolio heavy on high-tech holdings.
He has nearly $1.2 million in stock in Cisco Systems, an Internet networking company. He also owns smaller amounts of five other technology-related stocks and has more than $2 million in two money market funds, according to the Post. He listed no debt.
Nader, 66 and a lifelong bachelor, rents an apartment in Washington and does not own a car or real estate.
Nader said he does not take a salary from any of the public advocacy groups he founded during a decades-long career as a champion of consumer rights, and lives on just $25,000 a year.
In campaign speeches, Nader rails against the concentration of wealth and power by corporate America. But he makes no apologies for his own wealth, saying he could have been even richer had he not been funneling 80 percent of his earnings back into civic projects.
"I'd like to set an example that people who have means should use those means to better society," he told the Post.
Among the self-financed projects he cited are efforts to organize Public Interest Research Groups on colleges campuses. He also has started research centers devoted to health and safety, has worked on behalf of American Indian rights, child protection and solar energy education.
His running mate, Winona LaDuke, is an American Indian activist.
Other organizations he founded include Public Citizen and the Center for Auto Safety.
For decades, Nader refused to make public any of his personal financial information. Despite what appears to be a new openness forced by his long-shot presidential bid, he told the Post he would not release his personal income tax forms.
"Assuring privacy rights for all Americans has been one of my active engagements for many years," he said.