The comparison charts also add a 39 basis points reduction on the bond index, supposedly to simulate fees on a mutual fund. If you use a lower cost fund such as those offered by Vanguard index funds, the intermediate bond returns over time look much better than the higher cost stable value fund. Still, they are right that bonds are volatile. It is better to buy them when interest rates are comparitively high. The last good time to buy bonds was in 2000. Buying a bond mutual fund when rates are high maximizes the odds of being able to later sell shares of the fund at the same or higher prices. Rates are very low right now, and mutual fund prices are very high. Buying a bond fund now carries a high risk of taking a capital loss when you eventually sell the fund shares.