American women have made significant gains in law, medicine and other fields once dominated by men over the past four decades. But change has come more slowly on Wall Street, home of the New York Stock Exchange.

A stock exchange is a noisy place, filled with the sounds of traders buying and selling stock shares. On New York's Wall Street, as on many exchanges, those voices over the years have been mostly male. And Muriel Siebert says that remains true today. "Wall Street is still resistant because [it involves] money, and it's a tradition," she says.

But things are changing, with a growing number of women now holding seats on the New York Stock Exchange. Muriel Siebert was the first, and in her book Changing the Rules, she describes how she launched the trend. She says she didn't set out to be a rebel. In 1954 she left her hometown of Cleveland, Ohio for New York City. She was a college drop out with a gift for numbers. "If I look at a page of numbers, they light up and tell me a story. Don't ask me to spell. Don't ask me to remember a name, but I will remember numbers and annual reports. And the industry I got catered to my talents," she says.

Muriel Siebert, who goes by the nickname Mickie, did well at her first job, as a trainee at a New York brokerage firm. But she began to notice she wasn't being treated like her male colleagues. "If a company gave a luncheon at one of the luncheon clubs I could not go. They did not allow women in them. I was paid less. I changed jobs two or three times because the men doing the same work were making two times what I was making. It just wasn't right," she says.

In 1967, a friend suggested that if Mickie Siebert wanted to earn as much as she deserved, she should buy a seat on the New York Stock Exchange. There, she'd be her own boss, buying and selling stock shares for clients. It was something no other woman had ever done. "At first I thought he was ridiculous. But I took the constitution of the Stock Exchange home, and there was no law against it. I had to borrow money," she says. "A bank I was doing trust department business with said they'd give me a loan of 300 thousand dollars. But the Stock Exchange wanted that commitment in writing from the bank. And the bank told me, 'We've never had to write such a letter before. Get the seat, we'll give you the loan.' So I was in a Catch 22 [a problem with no way out]. And I had to find another bank to lend me the money. That was one of the roadblocks."

But Mickie Siebert says she was stubborn, she was a risk taker, and she had generous support. "The first day I had a seat, one of my clients called in an order [and said], 'We want to give you a first order to make sure your first month is successful.' The bank I borrowed money from called in an order," she says. "The commissions were what I owed them in interest for the first month. They said, 'We want to make sure you can pay your interest.'"

Over time, Mickie Siebert logged up an impressive list of achievements on Wall Street. The aerospace industry became one of her specialties, and when the struggling Lockheed Corporation requested federal aid, Mickie Siebert stepped in to help. She wrote a detailed report on how Lockheed's bankruptcy would have halted the production of innovative new flight technology. "It would have had real adverse effects on the airlines that had been buying the planes. And it also meant the country might have lost its preeminence in terms of building commercial planes," she says. "And I went down [to Washington, D.C.] and explained what I put into the letter to ten or twelve senators, and I was told it swung the vote."

Other women have sinced joined Muriel Siebert on the New York Stock Exchange. Laura Pedersen had started taking economics classes at the University of Buffalo at age 15, and at age 20, she became the youngest person to get a seat on the Exchange. She says by the time she arrived in the mid 1980s, the atmosphere had changed, at least in some ways. "If you made money as a trader and did your job as a clerk, they really didn't care if you were black, white, green, short, tall. It just didn't matter. But you certainly did notice you were in a very male-dominated environment," she says. "Nobody was holding the door. Nobody was saying 'Ladies first' at the breakfast table. And certainly the conversation when things got slow was usually cars, sports and women, and not necessarily in that order."

Laura Pedersen arrived on Wall Street at a time when traders were dealing in new kinds of investments like futures, gambling that the future value of a product would be higher than the price they paid for it today. She eventually made a fortune. "I went to Wall Street in January of 1984, and I had no idea it was the beginning of the biggest bull market in history," she says. "So as with anything new in business, oftentimes there is a considerable amount of opportunity there. And some of the people who had been down there a long time just weren't interested in it. They were more interested in stocks, and so if you were young, you could really jump on it."

Laura Pedersen has since left Wall Street and recently published Beginner's Luck, a novel about a teenager who loves to gamble. Mickie Siebert still works on Wall Street, but says she still feels like an outsider. "There are no other women-owned firms of any great size. I'm the largest one, and we're a peanut compared to the major firms," she says. "Yes, we get very fine rankings. We're number one Kiplingers online broker. We've been one of the top three brokers in general for smart money for the last five years. And I've made a decision that quality was better than size."

But even if she's still a minority, Mickie Siebert is also an institution. In the final weeks of 1999, she was among those invited to ring one of the last closing bells on the Exchange floor to mark the end of the millennium. She says the tribute felt great, a sign that no matter how controversial she'd once been, she's now recognized as a pioneer.