The quick move higher in the yields of Europe's weakest sovereigns from historic lows may be just the beginning and on the edges it could start to affect other low-rated credits where investors have hunted for yield—such as U.S. junk bonds.
Driven by speculation about the European Central Bank and selling by major investors, the prices of peripheral European bonds have been weakening since last week. As a result, the yields of sovereigns—Spain, Italy, Greece, Portugal and Ireland—have all moved higher, while the core German bund yield has edged just slightly higher.
The 10-year Spanish bond, for instance, was yielding 3.008 percent Tuesday, after reaching a low of 2.832 percent last Thursday, its lowest level in 20 years. As investors sell, Greece's 10-year yield is creeping back toward 7 percent, after making a four-year low of 5.85 percent in April.