The Impact of Rising Interest Rates on Bonds

An interest rate hike has been widely anticipated for some time. According to an October survey of 50 top economists conducted by the Wall Street Journal, the yield on the 10-year Treasury was forecasted to rise nearly one percentage point to 3.47% by the end of 2014. What impact would such a rise have on your investment portfolio?

First, Christopher Philips, a senior analyst in Vanguard’s Investment Strategy Group, points out the historical inaccuracy of such forecasts. For instance, a similar survey conducted in 2010 had economists predicting a 4.24% 10-year Treasury yield by the end of the year, an increase from 3.61% at the time of the forecast. In actuality, rates declines to 3.30% at year-end. The inaccuracy of these forecasts is well documented. In fact, as Allen Roth mentioned in the December issue of Financial Planning Magazine, a 2005 study by the University of North Carolina titled “Professional Forecasts of Interest Rates and Exchange Rates” found economists predict future rates far less accurately than a random coin flip would fare as a predictor.

Clearly, we can’t be confident what interest rates will do in 2014, but what if economists are finally correct and rates rise? How damaging would an interest rate increase be for bonds? If interest rates rise one percentage point next year, the intermediate aggregate bond index is expected to lose -2.8% -- far from catastrophic. Of course, such potential risk is notably minimal when compared to the downside of owning stocks (remember the -36.93% loss endured by the S&P 500 in 2008?).

It is also interesting to study how bonds have historically performed in periods of rising interest rates. Craig Israelsen, a BYU professor, recently documented how bonds performed during the two most recent periods of rate increases. Israelsen points out that although the federal discount rate rose from 5.46% to 13.42% from 1977 through 1981, the intermediate government/credit index had a 5.63% annualized return during that period. The next period of rising interest rates was from 2002 through 2006, when the federal discount rate had a fivefold increase: from 1.17% to 5.96%. During this period, the intermediate government/credit index obtained a 4.53% annual return. Clearly, even in an environment of rising interest rates, bond performance was surprisingly strong.

Most importantly, investors should never forget the value bonds add to a portfolio as a diversifier to stocks. Frequently, the performance of stocks and bonds are inversely related. For instance, when the stock market suffered during the tech bubble crash of 2000-2002, the Barclays Long-Term Government Bond Index rose 20.28%, 4.34%, and 16.99% in those years, respectively. More recently, when the S&P 500 lost -36.93% in 2008, the Long-Term Government Bond Index rose 22.69% during the year. This diversification benefit may prove useful when stocks ultimately cool off from the extended hot streak they have experienced since 2009.

In 2013, the Aggregate Bond Index decreased in value by -1.98%. Given the occasional negative correlation in performance between stocks and bonds, is it really surprising that bonds didn’t produce a positive return given the incredible year stocks had (S&P 500 up over 32%)? Additionally, held within a diversified portfolio, isn’t the -1.98% return produced by bonds during the recent equity surge a small price to pay for the additional security they are likely to provide when markets reverse?

In summary, it doesn’t seem prudent to avoid bonds entirely during periods of expected interest rate increases. First, forecasts of rising rates are far from certain. Second, even if interest rates rise bonds are still likely to be far less risky than stocks. Third, rising interest rates don’t necessarily mean declining bond values are a certainty – in fact, bonds performed quite well during the past two periods of rate increases. Finally, bonds are a vitally important part of a diversified portfolio, and owning uncorrelated and negatively correlated assets will be critical when equities ultimately lose their momentum.