Aggressive-growth funds ranked among the stars of the late 1990s bull market. At the time, technology stocks were climbing, and aggressive-growth funds attracted a flood of assets. Leading growth fund companies of the era included Pilgrim Baxter, Janus, and Putnam. But the highflyers crashed when Internet stocks sank in 2000. Since then, many of the aggressive-growth funds have gone out of business or toned down their approaches to focus on modestly priced stocks. One of longest-serving aggressive-growth managers is Robert Turner, who has been chairman of Turner Investment Partners for two decades. Despite suffering through the downturns, Turner has clung to his style of buying stocks with accelerating earnings. Now he argues that his approach is due to come back in favor soon. He says that aggressive-growth stocks had some periods of strong performance in the third quarter, and the style should come back to life as the economy continues growing slowly. "In a sluggish environment, investors will turn to stocks that can show rapid earnings growth," he says. Turner is bullish on technology. His Turner Large Growth Fund ( TCGFX) has 38% of assets in the sector. He says that champion companies such as Apple ( AAPL) and Google ( GOOG), should remain standouts, posting strong earnings gains at a time when most other companies will be sluggish. Turner is especially keen on data storage companies. The amount of data being generated is growing explosively as consumers around the world buy more smart phones and tablet computers. Every time you use a mobile phone to open a Facebook page, you generate data that is stored. Companies are spending heavily on data storage to learn more about how consumers are reacting. A favorite holding of Turner's is EMC ( EMC) which offers cloud-based systems that store and manage business information. Earnings have been increasing at a 19% annual rate. Another holding is Fusion-io ( FIO), which provides software that helps companies manage data. The company's revenue increased 82% in its last fiscal year. Management projected that revenue will grow 45% next year. Turner says that he is finding plenty of growth stars these days. The average annual earnings growth rate of stocks in Turner Emerging Growth is 15.8%. Such stocks could soar if the economy continues growing. That could result in big gains for investors who have the stomach to buy aggressive- growth funds at a time when the market outlook appears shaky. This article is commentary by an independent contributor, separate from TheStreet's regular news coverage.