Taxable bond mutual funds have lagged the stock market in the past 10 years, but they’re looking steadier amid the stock market sell-off. The average taxable bond mutual fund rose an average annual 4.32% the past 10 years vs. 6.61% for the S&P 500. A $10,000 investment made in the average taxable bond fund on June 20, 2005, would have risen to $15,611 by Sept. 29 this year, according to Morningstar Inc. data.