''In the past six years, technology companies have shown earnings growth of about 30% per year,'' he points out. ''That's nearly four times the 8% earnings growth rate of the S&P 500 over the past 65 years and more than twice the 14% growth rate of that index in the past six years. We believe that this level of earnings growth can continue, which suggests that technology stocks are more fairly priced after the recent correction, creating value and opportunities. Where else should a growth fund invest if not in technology?'' 

  Considering these views, Ballen is surprisingly unbloodied this year. As of Morningstar's last report, after the first quarter of 2000, his MFS Emerging Growth Fund was almost 68% invested in technology stocks and another 19% in services, including many telecommunications companies (MCI Worldcom, for instance) that are tech's first cousins. Considering this extreme exposure and the beating technology took in the first five months of 2000, with the Nasdaq composite off more than 16%, Ballen's results were respectable, down less than 6%. 

  Unfazed by a bear market that many investors thought was long overdue, Ballen continues to back technology stocks. ''Every sizable company around the world is making major investments in technology,'' he says. ''This is a long evolution, a long game in which we're far from the last innings. Technology investing has become a secular story rather than a cyclical one. Not long ago, companies could cut back on technology spending when they had poor years. Now, they have to keep spending if they want to compete. It's the same for companies in Japan, in Europe, and all over the world. Japanese companies, for example, pay half as much for technology as U.S. companies do, and they're going to have to increase spending in order to catch up.'' 

  Ballen's record lends credence to his views. Although other names may come to mind, John Ballen, 40, is arguably the most influential person in transforming the Boston-based mutual fund company from a stodgy bond fund shop into a fund-raising leader now, especially in equity funds. The company was not always known for its stock answers. ''In the mid-1980s we were strong in fixed-income, but we didn't have a culture of success in equities,'' says Kevin Parke, MFS Investment Management's chief equity officer. 

  That image has changed, largely due to the record of Ballen, who joined the firm in 1984 as a research analyst. He was named portfolio manager of the startup Emerging Growth Fund in late 1986 and assumed the title of research director in 1988. It was "the best move I ever made,'' says Jeffrey Shames, chairman and CEO of MFS Investment Management. 

  The big breakthrough occurred in 1991, when Ballen's fund posted an 88% return, 57 percentage points better than the S&P 500 and 31 percentage points higher than the average return for small-cap growth funds (that's where Emerging Growth was back then), as calculated by Morningstar. The fund went on to string together excellent years through 1995, slumped a bit through 1998, then recovered to close the 1990s with a 49% return last year. For the decade, Emerging Growth returned almost 25% per year, nearly 7% ahead of the S&P 500 (which it beat seven years out of 10), to make it the fourth-best equity fund for the period. 

  From a relatively obscure $76 million fund at year-end 1990, Emerging Growth lived up to its name, burgeoning into a $20 billion juggernaut at the turn of the century. Ballen's secret, simple in hindsight, was to buy tech stocks and let his winners ride. "I bought Oracle back in 1990,'' he recalls, ''when the company was virtually penniless, near bankruptcy, and I bought Cisco Systems in 1994 and 1995, at 10 to 12 times earnings, before most people had heard of the Internet.'' Adding to his positions but not selling, he watched both stocks appreciate until they ranked among the top seven of all U.S. companies, by market value, in early 2000. By last spring, his fund had weightings of 22% and 14% in Oracle and Cisco, respectively. 

  (He also bought Microsoft in the late 1980s, riding the stock up but seeing it stumble recently. At nearly 4% of assets, Microsoft was the firm's fourth-largest holding, as of last report, behind Tyco International.) 

  Although Ballen prefers to let winners ride, he routinely reduces positions when they start to dominate the fund. ''We've been selling Oracle and Cisco lately,'' Ballen says. ''We still think these are outstanding companies, leaders in their industries, but we've decided to trim our outsized positions. Nevertheless, they continue to be our largest holdings. Oracle doesn't seem to be as threatened by Microsoft as it did a few years ago, and Cisco is extremely well-managed." 

  If Emerging Growth plans to sell off some Oracle and Cisco, its stellar tax-efficiency may fall off. The fund has held turnover to 22% or lower each year since 1994 (the average for the large-cap growth category is 95%) and kept capital gains distributions to 41 cents per share or less in each of those years. Combined with a lack of income dividends, the fund has a 99.4% tax efficiency for the past five years, Morningstar reports, and a 98.4% tax efficiency for the trailing ten years, substantially ahead of category averages.