Spooked by conflicting movements in interest rates and a stock market in the doldrums, mutual fund investors are beginning to wonder if they should leave their money with the aggressive growth funds. These high-capital appreciation funds topped investment performance ratings during the past year's bull market.
Still, investors remember that the highly speculative funds, which have historically performed well during roaring bull markets, tend to fall faster and further than other funds when the market turns bearish. Thus, some investors may now be searching for more conservative funds.
During the third quarter, notes Sheldon Jacob, publisher and editor of the ''No-Load Fund Investor,'' a quarterly newsletter that tracks the performance of some 300 no-load funds, ''it was a period of correction. And when you get into a correction, the leading funds tend to be the conservative funds - the income funds.'' So according to Mr. Jacobs's calculations for the third quarter - which precede by several weeks the funds' public announcements - mutual funds like the Windsor Fund, ''a very sluggish growth fund,'' and some international growth funds have outperformed the aggressive mutual funds.
For the nine months ending Sept. 30, however, the high-flying aggressive growth funds have continued to keep their lead in the performance sweepstakes. ''The average aggressive growth fund is down only 2 percent or 3 percent during the third quarter.'' And since their performance earlier in the year outdistanced by far all other contenders, most aggressive growth funds show superb results so far this year.
Hartwell Leverage Fund, for instance, was up 79.5 percent for the year ending Sept. 30. Fidelity Technology is up 133.4 percent in that same time frame, and Fidelity Magellan Fund is up 83.6 percent. Delta Trend Fund, the highest performer for the the first six months of 1983, at 73.13 percent, is up 58 percent for the first nine months.