NEW YORK ( TheStreet) -- The Barclays Aggregate bond index has been a tough bogy for managers to beat. During the past decade the index returned 5.7% annually, and only about a quarter of actively managed intermediate-term funds topped the benchmark. Many of the winning managers succeeded by taking on more risk. The funds held sizable stakes in high-yield bonds, which are rated below-investment grade. Since the financial crisis, high-yield bonds have rallied sharply and boosted fund returns.But some intermediate funds have topped the benchmark without holding big high-yield positions. Focusing on high-quality securities, the funds have succeeded by spotting undervalued bonds. The high-quality funds could make sound core holdings for cautious investors. Solid performers include Artio Total Return Bond ( BJBGX), Touchstone Total Return Bond ( TCPAX), and Wells Fargo Advantage Total Return Bond ( MNTRX).