"In some cases, you've got better yields than may be available out of the U.S. for what might be similarly rated credit," Schmieder says. "You get more yield for a similar rating, or in some cases, more yield for a lesser default risk."
They also provide an element of asset diversification for U.S. investors, Schmieder says. "Just as you would in equities, why wouldn't you be diversified across your fixed-income portfolio?" Schmieder asks.
Richelson says because their performance isn't directly tied to the U.S. economy, their price and value won't always move in the same direction as those of U.S. bonds. At a time when the U.S. economy is still on shaky ground, that can be appealing.
Lastly, investing in Yankee bonds gives investors the ability to capture some of the growth occurring outside the U.S. "You can tap into growing emerging market economies by buying bonds of companies that are represented in those countries," he says.
A kinder, gentler foreign bond?
While their higher yields and diversification have long drawn American investors to foreign bonds, Yankee bonds have a few key advantages over their conventional siblings. The biggest benefit is they insulate investors from currency risk, says Annette Thau, author of "The Bond Book." Because U.S. investors will eventually have to convert proceeds from investments denominated in foreign currency back into dollars, currency fluctuations can have a big influence on overall returns. Put simply, if the dollar gets stronger against a foreign bond's currency, that bond won't be worth as much to an American investor.
"If you're buying a bond in a foreign currency, then currency risk becomes predominant," Thau says.
By being issued in dollars, Yankee bonds avoid this currency risk, Thau says.
American investors are also attracted to Yankee bonds because they are regulated by the Securities and Exchange Commission and are rated by American ratings agencies such as Moody's Investors Service and Standard & Poor's.