Last week's increase in the money supply, combined with Wall Street's gains last week in anticipation of Federal Reserve Chairman Paul A. Volcker's reappointment, left stock and bond investors in limbo today with key stock measures showing slight declines.

Wall Street experts said today, however, that they expect more telling signs of the close of the lengthy Volcker saga to come later this week as the government holds major auctions of four-, seven- and 20-year bonds.

"If you view the bond market as a poll, today might not have been the best day to do the polling," said Maury Harris, senior financial and business economist at Paine Webber Inc. "Let's wait and see the polling in the four-year action."

But with the Dow Jones Industrial Average showing a 46-point gain last week, pinned primarily on anticipation of Volcker remaining in his spot atop the nation's central bank, market analysts said that there was little reason to think that stocks would continue their large gains today.

Analysts particularly cited Friday's announcement of the $5.6 billion increase in the money supply for the week ended June 8.

As a result, the Dow industrials fell by three points to close at 1,239.18, with volume on the New York Stock Exchange down sharply to 84.2 million shares from Friday's total of 96.6 million.

Bonds also were generally lower today as the federal funds rate traded at 9 1/8 percent throughout the session and both municipal and corporate bonds were off slightly in limited trading.

With the uncertainty that surrounded speculation on Volcker waning, market analysts said that trends in the market are likely to reflect fundamental economic and investment analysis rather than the ups and downs of Washington political rumor.

Moreover, analysts said today that the long-term Wall Street view, generally reflected in the bond markets, is likely to begin to be affected by looming large budget deficits.

Now that President Reagan has decided to renominate Volcker, "the keys to getting the bond market to move are alterations in fiscal policy," said Steven Einhorn, vice chairman of the investment policy committee at Goldman Sachs & Co. "The deficits make a positive long-term view very difficult."

Einhorn also predicted that in securities markets, "there is some inevitability" to retreating stock prices of about 10 percent, especially since the market has gained about 65 percent over the past 10 months.

But on the Street today, the mood was upbeat and some analysts suggested that stock prices might have fallen more sharply if it were not for Reagan's surprise announcement Saturday. "For once, the most competent person seems to have won," Harris said.

Nevertheless, each of the four Dow averages fell today. Furthermore, the New York composite index was down 0.04 to 97.96 and the average price per share fell by 1 cent.

There were 726 advancing stocks, while another 885 fell. On the American Stock Exchange, volume was down slightly from Friday's 11.9 million shares to 11.5 million shares.

The Amex index, however, was up 2.07 to close at 482.71, and the average price per share was up 8 cents. Declining Amex stocks led advancing issues by a total of 356 to 319, while 168 stocks were unchanged.

Nationwide turnover in NYSE-listed issues, including trades in those stocks on regional exchanges and in the over-the-counter market, totaled 98.07 million shares.

Standard & Poor's index of 400 industrials was unchanged at 190.68, and S&P's 500-stock composite index was down .11 point at 169.02.

The Nasdaq composite index for the over-the-counter market dropped 1.48 points to 324.63.

Point-plus gainers in the tobacco group included Philip Morris, up 2 3/8 at 60 5/8; R.J. Reynolds, up 2 1/2 at 53, and American Brands, up 1 1/8 at 50 3/4. Analysts said Reynolds' recent announcement of a cigarette price increase eased fears of mounting price competition in the domestic market.

In the casino gambling group, Golden Nugget rose 4 1/2 to 88; Bally's Park Place 1 1/8 to 24 1/8, and Caesars World 3/4 to 17 5/8. At the American Stock Exchange, Resorts International class A climbed 3 1/2 to 49 1/2; Elsinore 1 to 14 1/4, and Caesars New Jersey 3 to 31 3/4.