As we’ve noted before bond investors around the world tend to harbor a strong “home bias”—a preference for domestic over foreign assets. This bias can be found in most core bond portfolios, which aim to provide investors with stability and income by focusing on investment-grade debt and holding a healthy share of government bonds.
Our research, however, suggests that global bonds have offered historical returns comparable to domestic ones—and with considerably lower volatility. What’s more, varied global exposure offers investors diversification of interest-rate and economic risk. That’s important today, as business cycles, national growth rates, monetary policies and yield curves around the world diverge.
Less Volatility, Better Risk-Adjusted Returns
But adding global isn’t just a tactical strategy for dealing with uncertain market conditions. A hedged global bond portfolio that strips out currency volatility can meet an investor’s core objectives of stability, income and diversification against equities. In other words, the ideal core portfolio should, by definition, be global.
When looking at the three-year rolling standard deviations of three different bond strategies—a hedged and an unhedged global approach and a US-only approach—over the past two decades, we found that the unhedged strategy was considerably more volatile than the US-only approach.
But here’s the part that may surprise some people: it was the hedged global strategy that had the lowest volatility of all—and investors did not have to sacrifice returns in the bargain. In fact, our analysis shows that returns over the period were about the same for all three strategies. But risk-adjusted returns were highest for the hedged global approach (Display).
Protecting Against Interest-Rate Risk
A global approach also offers protection when US bonds stumble. We reviewed quarterly returns between 1990 and 2013 and found that when the Barclays U.S. Aggregate Bond Index was positive, it returned 2.4% on average. The hedged global aggregate performed nearly as well, capturing 94% of those gains. We call this the “up capture.”
The “down capture” was a different story. To be sure, when the Barclays US Aggregate was negative, the hedged global aggregate was also negative. But its “down capture” was just 67%. In other words, we found that the hedged global approach captured nearly all the returns of the Barclays US Aggregate during positive quarters, but only about two-thirds of its average quarterly loss.
Over the years, those investors who shifted away from the US and toward other countries where rates were either rising more slowly or falling preserved more of their capital. That may be worth keeping in mind if, as expected, the US Federal Reserve is one of the first developed-market central banks to start raising policy rates in the year ahead.
Diversification When You Need It Most
Finally, we found something similar when looking at correlations. Since 1970, US Treasuries have shown a low correlation to UK, German, Japanese and Italian sovereign bonds. And the correlations were in many cases lowest during extremely negative months for Treasuries—in the case of German bunds, they fell by almost two-thirds during those months.