Muriel Siebert

Financier and honoree Muriel Siebert speaks on stage during the Brooklyn Museum's Sackler Center First Awards at the Brooklyn Museum in 2012. (Neilson Barnard / Getty Images)

Muriel Siebert, whose success as one of Wall Street's early, influential female analysts earned her the contacts and nest egg to become the first woman to buy a seat on the New York Stock Exchange, has died. She was 84.

Siebert died Saturday of complications from cancer at Memorial Sloan-Kettering Cancer Center in New York. Her death was confirmed to the Associated Press by Jane Macon, a director of Siebert Financial and a partner at the law firm Norton Rose Fulbright.

[For the Record, Aug. 26, 2013: A previous version of this story reported that Siebert was born Sept. 12, 1932, and was 80 when she died, according to information supplied by a spokeswoman. In fact, she was born Sept. 12, 1928, according to Ohio birth records, and was 84 when she died.]

In paying $445,000 for one of the NYSE's 1,366 memberships on Dec. 28, 1967, "Mickie" Siebert broke up the all-male bastion of the Big Board, which until then had permitted women on the trading floor only as clerks and pages to fill shortages during World War II and the Korean War.

The lack of enthusiasm for welcoming a female colleague was evident, Siebert said, in her search for the two sponsors she needed under membership rules. After several rejections, she got James O'Brien, a partner at Salomon Bros. & Hutzler, and Kenneth Ward, a partner at Hayden Stone & Co., to back her.

Much of the opposition was couched as kindness.

"There was all manner of concern for my delicate ears — with several articles postulating that a woman couldn't handle the rough language of Wall Street — and many comments about the absence of a ladies' room on the Stock Exchange floor," Siebert recalled in her 2002 memoir, "Changing the Rules: Adventures of a Wall Street Maverick," written with Aimee Lee Ball.

"Not since I was a baby had so many people been so interested in my bathroom habits," she wrote.

Siebert's revolution was at least partly symbolic, since she did most of her work away from the floor, researching companies and advising clients of her sole-proprietor firm. Her stock-exchange membership meant that she could, when she desired, handle the actual buying and selling of securities, giving her a larger share of commissions.

Of the 62 traders, brokers and investors profiled by Martin Mayer and photographed by Cornell Capa for the 1969 book "New Breed on Wall Street," Siebert was the only woman. The book was subtitled "The young men who make the money go."

In 1975, when the Securities and Exchange Commission moved Wall Street from fixed commissions to negotiated ones, Siebert retooled Muriel Siebert & Co. into a discount brokerage, cutting her rate in half for individual investors.

She went on to serve five years as New York State's first female superintendent of banks. Following an unsuccessful bid for the Republican nomination for U.S. Senate in 1982, she returned to her brokerage, which she took public in 1996 under the holding company Siebert Financial Corp.

The brokerage offered clients the option to trade online, and for two brief periods in 1999, as Internet-related stocks soared, her 90%-plus ownership stake made her, on paper, a billionaire. Within months, about $700 million of that disappeared.

Siebert, who had seen similar bubbles burst before, said she hadn't let her hopes ride with the share prices.

"The day-traders giveth and the day-traders taketh away," she said in a November 1999 interview. Of her paper billion, she added: "At least I didn't write a check for that amount."

Siebert was born Sept. 12, 1928, in Cleveland, the daughter of Irwin Siebert, a dentist, and the former Margaret Roseman.

As she told it in her memoir, she left home for the first time in 1953 for a summer trip to New York City with two friends and "a busload of other gawking tourists." During a guided tour of the NYSE, she remembered looking down from the visitors gallery at a "sea of men in dark suits."

Siebert at the time was a student at Cleveland's Flora Stone Mather College, the women-only school at Western Reserve University, today's Case Western Reserve University. As the only female student in a money-and-banking class at the men's college, she recalled, she was known as "the delegate from Mather."

Her father's death from cancer during her junior year prompted Siebert to look for work before finishing her undergraduate degree. Plus, "I was cutting class and playing bridge," she said in a 2010 Wagner College commencement address.

In 1954, she drove to New York in a used Studebaker to live with her older sister, who was working in public relations.