NEW YORK -- For all the attention paid to Michael Milken and greed on Wall Street in the 1980s, the surprising fact is that the real mountain of money has been piling up in the 1990s.

A few facts:

* The three most profitable years in the history of the U.S. securities industry were 1991, 1992 and 1993.

* So far this decade, the member firms of the New York Stock Exchange have made nearly $22 billion before taxes, only $5 billion shy of the total for the 1980s and roughly double what they made in a comparable period in the 1980s, according to industry data.

* Wall Streeters have drawn $100 billion in salaries and bonuses so far this decade, which is nearly three times the compensation earned in the same period in the 1980s.

"There are hundreds of traders who make $5 {million} to $15 million a year," said Gary Goldstein, president of the Whitney Group, an executive recruiting firm in New York City. He added that there are "hundreds of salesmen who make north of $2 million, hundreds of bankers making between $1.5 {million} to $5 million a year."

* A middling broker or trader makes $200,000 a year, according to industry data.

* Superstars such as speculator George Soros make staggering amounts. Soros garnered roughly $1.5 billion from fees and profit on his personal investments in 1993, according to sources close to him. Milken in his best year made a shabby $500 million.

* Classy investment bank Goldman Sachs & Co. -- whose co-head until 1993, Robert E. Rubin, is now a key adviser to President Clinton -- earned $2.7 billion before taxes and payments to outside investors last year. In 1989, Goldman made a paltry $750 million.

After paying Uncle Sam and outside investors their share last year, Goldman had slightly more than $1 billion to be divvied up among 160 general partners, according to sources at the firm. (The $1 billion excludes capital gains they made on the $3.7 billion they had invested in the business at the start of the year.) That works out to an average of $6 million per partner, although most got a lot more than that.

* Financial World magazine's 100 best-paid Wall Streeters had a cutoff last year of "at least $10 million," and there was a separate list for Goldman partners.

So far, 1994 has been mediocre compared with 1993's record profits. Rising interest rates have clobbered bond prices and investors have grown a bit more wary of stocks.

But the long-term prognosis for Wall Street remains excellent nonetheless. "We could be in for some rough weather," said James Dimon, president of Travelers Inc., which owns the brokerage Smith Barney Inc. "But this business is not going to stop. Americans are the world's experts in financial engineering. The demands for our services are tremendous."

The staggering prosperity of Wall Street raises many questions, especially at a time when millions of average Americans are struggling to maintain their standards of living.

Not the least of them is: Where is all this money coming from?

"From almost every part of the business," answered Dimon.

Unlike the 1980s, when Wall Street's hottest activity was "M&A," short for mergers and acquisitions, the sources of income now are broader.

Wall Street sources say the four great businesses of the 1990s are issuing stocks and bonds; trading securities and other investments, especially for a firm's own account; managing other people's money; and expanding into overseas financial markets.

The first of these cash cows is issuing stocks and bonds. It is impossible to exaggerate the blizzard of new paper securities printed by Wall Street in the '90s. In 1993, there were 6,468 new underwritings for companies in the United States, compared with only 1,830 in 1990. Every time a new security is issued, Wall Street takes investment banking fees. The bigger the deals, the bigger the fees.

The value of new bonds and other debt securities issued in the United States has more than tripled since 1990, rising from $519 billion to $1.858 trillion as of June of this year. Stocks have shown even faster growth; the value of new issues rose from $542 billion in 1990 to nearly $2 trillion as of last month.

"That is a surge," says Roy C. Smith, professor of finance at New York University and a former general partner at Goldman Sachs. "And when you have a surge like that, you create manna for everyone to chomp on."

The story behind the surge is fairly simple.

As interest rates declined to record lows during the early '90s, companies and governments saw an opportunity to raise money cheaply by selling bonds paying less interest or shares at historically high prices. So they went to Wall Street, which found hungry buyers for the new paper among mutual funds and other large investors.

Today, big borrowers increasingly turn to Wall Street for money instead of commercial banks.

The second, and most lucrative, business for Wall Street in the 1990s has been trading securities, according to analysts.

Last year, the New York Stock Exchange traded shares worth $265 billion, more than three times the volume 10 years ago. Trading in bonds, a far larger market, rose similarly.

"On a slow day, our desk does $350 million," says Louis A. Schneider, Smith Barney's head U.S. over-the-counter stock trader. "On a busy day, we do about $750 million." His colleague Robert S. Adrian, who runs trading in listed U.S. stocks, estimates that his desk does from $300 million to $500 million a day.

Proprietary trading -- that is, trading for yourself rather than for customers -- is where Wall Street has made a ton of dough in the 1990s.

"The profits on trading securities for customers have plummeted as large investors have become more sophisticated and powerful," said research analyst Guy Moszkowski of Sanford C. Bernstein & Co. "So {the Wall Street firms} must risk their own capital and trade for their own accounts to make the kinds of returns they want."

Not least among these proprietary traders has been Goldman Sachs. "Proprietary trading made substantially more for us in 1993 than the customer business did," said an executive at Goldman.

At Goldman, say sources at the firm, one of the big proprietary trades last year was a bet on German bonds and against French bonds. Goldman made hundreds of millions of dollars on the trade, say the sources.

Goldman is not alone. Salomon Inc. head Deryck C. Maughan told analysts recently that the firm generally makes $500 million to $1 billion a year on proprietary trading. That may explain why Maughan paid foreign exchange trader Hans Hufschmid at least $20 million last year, according to numerous press reports.

The third great gusher on Wall Street has been investment management. As Americans pulled their savings out of low interest rate bank accounts and switched into stocks and bonds, Wall Street was swamped with money to be managed. For a fee, of course.

The leaders include not only the big investment banks such as Goldman, but also mutual fund companies such as Fidelity Investments. About $2.2 trillion has come into mutual funds, 10 times the pot in the early 1980s.

Investing other people's money -- known to the denizens of lower Manhattan as "OPM" -- is low-risk and high-profit. It doesn't take many people or much in the way of plant and equipment to oversee a pot of money, according to Michael A. Flanagan, securities industry analyst at Lipper Analytical Services Inc.

He notes that the more money a firm has under management, the greater the "economies of scale." As more money comes in, the cost of managing it goes down because someone managing $100 million probably can do as decent a job with $500 million. No need to quintuple the staff. So costs go down.

The savings tend not to be passed along to customers, however. A recent study of profits at six publicly held mutual companies by Lipper Analytical Services Inc. shows this clearly.

Take Dreyfus Corp., a mutual fund company recently bought by Mellon Bank. As money under management rose 37 percent from 1990 to 1993, its pretax profits rose a stunning ten-fold.

The final bonanza for Wall Street has been the overseas business. To put it plainly, U.S. securities firms are simply kicking the stuffing out of foreign competitors.

"American firms are the pacesetters," said Paul Isaacs, chief economist at Mabon Securities Corp. "As capital flows become increasingly international, the Americans have emerged as first-tier players in all markets and countries."

For the first time in the history of international finance, Wall Street firms, and a few U.S. commercial banks, are becoming leaders in markets traditionally dominated by local outfits.

Of the top 20 securities firms in the world as of 1993, 15 are American, according to industry rankings.

Smith says that the supremacy of the U.S. firms is easy to explain. "We have had integrated securities firms for decades," he said. "Overseas, they are just starting to splice together trading, brokering and investment banking... . They are like people standing around waiting for a bus. The U.S. firms are just moving ahead."