The Dividend Dip Indicator is flashing a sell signal for stocks. According to the D.D.I., if more companies are raising dividends than during the same period last year, investors should sell. If fewer companies are raising dividends, stocks are a buy. About 12 percent more companies raised their dividends during the past 12 months, making the indicator bearish. Investors who have followed the D.D.I. signals since 1956 have made 1,087 percent on their money, vs. 434 percent for those who merely bought and held.

- Sogen International Fund in New York City is one of the most eclectic funds around - mixing U.S. blue-chips with Dutch growth stocks, Japanese bonds and Australian gold mines. Sogen will buy anything that meshes with manager Jean-Marie Eveillard's philosophy: "Avoid losing money. If you don't lose money, your record will take care of itself." Sogen's record has. It's up 479 percent over the past 10 years. Recent favorite stocks: Greif Bros., Bank for International Settlements, A.P. Green, Hancock Fabrics, Western Mining, Coors, Minorco.- Surging oil prices will soon make exploration in the United States economically feasible again. That's good news for the oil service stocks that have been among the market's worst performers in recent years. Philip Dodge of Nomura Securities believes the first issues to turn around will be those that provide offshore services: Baker Hughes (drill bits), Halliburton (pumping), Schlumberger (underground testing).

- Undervalued stocks are always going to be takeover candidates. That's particularly true if they've been using earnings increases to pay off debt and build cash reserves. Steven Colbert of Prudential-Bache likes three solid capital-equipment companies that have been doing just that. He reckons all three are worth at least 80 percent more than their current market price to a potential bidder: Clark Equipment, Ingersoll Rand, Sundstrand.

- Margo's Market Monitor (P.O. Box 642, Lexington, MA 02173) made a nice profit in gold in September 1986 when market conditions were quite similar to today's. Now M.M.M. is bullish again. "Both silver and gold peaked in 1980 - nine years ago. Silver, in particular, is depressed. In 1980, it was $48.50 per ounce. Now it's $6. With OPEC holding firm, oil is close to $20 per barrel, vs. the $5 everyone envisioned not long ago. This is bullish for the metals."

- Of 500 taxable bond funds in the United States, only 19 invest across the entire fixed-income spectrum. Of these, FPA Income in Los Angeles is one of the most successful. FPA currently favors long-term Treasuries, considering the extra yield from corporates or junk bonds "too small for the added risk." FPA also likes some convertible bonds selling at deep discounts from par value. Like Seagate Technology 6.75 percents of 2012 and Magna International 7 percents of 1993.

- The stock market is still struggling to regain its pre-crash peaks. But according to Mutual Fund Forecaster (3471 N. Federal Highway, Fort Lauderdale, FL 33306) 35 mutual funds have already surpassed those levels. Here are the best-performing among them excluding specialty funds: Calvert-Ariel Growth (up 25 percent since the market peak), Lindner Dividend (up 13 percent), Mutual Series-Shares (up 9 percent), Paine Web-ber Asset Allocation (up 9 percent.)

Investor's Notebook reflects the opinions of professionals. It does not endorse specific investments, and no endorsement is implied or should be inferred. For more information, contact the individual firms cited. (C) 1989 Universal Press Syndicate 4900 Main St., Kansas City, MO 64112