Stable-value funds are a lot less risky than stocks, but be a little skeptical in this market of any promise of 100% stability. By Kimberly Lankford, Contributing Editor October 30, 2008 In my 401(k) plan, I have money in Promark Income fund, a stable-value fund. How risky is this type of fund? Also, is this a good substitute for some of the bond portion in a diversified portfolio?Stable-value funds sure are a lot less risky than being in the stock market. And so far, they've done a great job of maintaining their stability. David Babbel, coauthor of a study on these funds, says none has ever experienced a decline in value. Promark Income fund, run by General Motors Asset Management, returned 5.1% over the past year through September 30 and an annualized 5.6% since its inception on December 31, 1998. A spokesman says the fund invests in a full spectrum of fixed-income instruments, including money-market funds and corporate bonds. As with all stable-value funds, principal is guaranteed by a "wrapper" from an insurance company. In this specific case, three double-A-rated insurers guarantee the fund's value. Babbel says three safeguards "act as a pretty good safety net to keep stable-value stable": the funds' own investment guidelines, the accounting standards the funds use, and the insurance company's credit-quality requirements. Advertisement Babbel's study, which examined these funds from their inception in 1989 through 2007, found that they typically outperformed money-market funds and intermediate-term government-bond funds while delivering a guaranteed quarterly return. So you could use Promark Income for a portion of your bond investments. Keep in mind, though, that with global financial markets in turmoil, any promise of 100% stability has to be taken with at least a tiny bit of skepticism. Got a question? Ask Kim at email@example.com.