In a search for top mutual-fund companies, don’t ignore the little guy, said Jonathan Burton in With fewer assets under management, such firms are often in a better position to “ride bull runs and sidestep a bear’s swipe.” Among the top quartile of managers, 40 percent have less than $2 billion in total assets under management, according to research by Northern Trust, a large investment management firm. If you’re thinking of trusting your money to a boutique shop, make sure it has a “spotless record” with regulatory agencies and incentives tied to fund performance. Also, be wary of small funds that suddenly become popular. Rapid growth may overwhelm a sharpshooting firm, says Northern Trust’s Ted Krum. That may mean investing has taken a back seat to marketing.