For the first time in eight years, Japanese investors were net sellers of U.S. securities last year, notes The Gran-dich Letter (4667 Route 9, Suite 12, Howell, NJ 07731). "This trend is continuing. Japan will be a small player in the U.S. financial markets for the foreseeable future due to higher Japanese interest rates and attractive alternative investments in Europe. Whatever gains American companies may experience overseas will be wiped out by the outflow of foreign capital from our stock and bond markets."

- "It takes a strong stomach and a stiff backbone to buck the conventional wisdom," admits Windsor Fund's John Neff. Neff buys "overlooked, misunderstood, woebegone" value stocks selling at low multiples to their earnings and dividends. Current favorites: Aetna, Ahmanson, Bank of America, Chrysler, Cigna, Citicorp, Ford, Golden West Financial.- With a recent price-earnings ratio of just 8-to-1, the Spanish stock market has reached its lowest level since 1984, observes Prescott, Ball & Turben in Cleveland. "At this level, the Spanish market is already discounting a recession and seems unrealistically undervalued. Spanish growth and earnings prospects are still better than most of Europe's." Prescott's favorite special situations and interest-sensitive issues: Acesa, Aumar, Cofir, Europistas, Hidrola, Sotogrande.

- In the past five recessions, the stock market lost an average of 22.3 percent, notes Boetcher & Co. in Denver. "But some industry groups held up better than others. The best-performing sectors during the past five slowdowns: gold (up 3.8 percent), tobacco (up 0.9 percent) and drugs (down 7.1 percent). The worst-performing sectors: pollution control (down 36.1 percent), low-priced stocks (down 32.4 percent) and computers (down 30.3 percent)."

- Over $20 billion in junk bonds defaulted last year. Another $50 billion is expected to default by the end of 1992. But where there is danger there is also opportunity, declares Forbes' Matthew Schifrin, who recently surveyed Wall Street's most respected junk analysts on their favorite issues. Schifrin came up with a list of bonds with yields ranging from 13 percent to 20 percent despite relatively strong balance sheets and recession-resistant businesses: Caesars World, Coltec Industries, Duracell Holdings, Loehmann's Holdings, Mesa Capital, Owens-Illinois, Play-tex Family Products, SSC Holdings, United Airlines, Vons.

- Closed-end country funds now sell at some of their biggest discounts in years. "But they should catch up to their underlying values soon, producing significant profits for those who buy now," says International Fund Monitor (P.O. Box 5754, Washington, DC 20016). "Our two favorite funds are Singapore, whose market is languishing but still offers good long-term prospects, and the Latin American Fund. Other buys: Austria, First Australian, Growth Fund of Spain, Jakarta, Japan OTC, Korea, Malaysia, Mexico, Swiss Helvetia, Thai Capital, United Kingdom."

- Don't feel bad if you can't afford a private money manager. According to CDA Investment Technologies, the portfolio of the average private manager fell 6.1 percent last year, vs. the Dow Jones industrial average's loss of just 4.3 percent. The best-performing managers, said CDA, had most of their money in large-cap stocks and were highly concentrated. Among the top 20 performers, only five owned more than 100 different stocks.

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.