"Ultra-short" set the style in 2008 in top-performing exchange-traded funds. Since ETFs offer lots of "inverse" funds, which rise when indices fall and vice versa, those topped the list during the dismal year that just ended. Inverse-leveraged funds, which use borrowed money to amplify gains, did even better. Of 620 ETFs tracked by TheStreet.com Ratings for which complete 2008 returns are available, 71 managed to avoid the maelstrom that brought down many popular equity indices by 30% or more. Most of the winners were inverse funds. An accompanying table lists top-performers in broad classifications of ETFs. Short funds were tops among inverse and leveraged offerings, particularly technology and growth funds. Anyone tempted to join that party should look at the column of December returns. A modest upturn in the market can hit holders with depressingly quick double-digit losses. As the Federal Reserve lowered interest rates, the few ETFs that focus on long-term Treasury bonds easily outdistanced other investments on the "long" side. The three top-performing bond ETFs in the table achieved impressive returns over one month, three months and one year. Among non-leveraged equity funds, health and biotechnology funds dominated, confounding some experts. The top three in that area moved up smartly in December, although only one managed a positive total return for the year. Although it lost ground during the final quarter of 2008, HOLDRs Biotech ( BBH) finished the year with a net gain of 10.2%. Its top stocks include Genentech ( DNA), Amgen ( AMGN), Gilead Sciences ( GILD) and Biogen IDEC ( BIIB).