Foreign government bonds in developed markets roared last week, generating the strongest performances among the major asset classes, based on a set of proxy exchange-traded funds.

Leading the way higher: SPDR Bloomberg Barclays International Treasury Bond (BWX) surged 2.2% over the five trading days through May 19, rising to its highest weekly close since last October. A key source of BWX’s strength: the decline of the US dollar, which fell to a seven-month low on Friday, based on the US Dollar Index. BWX’s portfolio of foreign bonds is priced in unhedged US dollar terms. All else equal, a decline in the greenback lifts the value of foreign-denominated assets after translation into US dollars.

Note that other slices of foreign bonds among the major asset classes held the second- and third-place slots for performances last week: iShares International High Yield Bond (HYXU) and PowerShares International Corporate Bond (PICB), respectively.

On the flip side, emerging-markets equities posted the biggest loss last week among the major asset classes, albeit suffering only a fractional setback. Vanguard FTSE Emerging Markets (VWO) edged down 0.6%.

VWO’s latest weakness looks like noise, however. The bullish trend for the ETF remains conspicuous over a longer-term horizon. For the trailing one-year period, for instance, VWO is firmly in the top spot, posting a 28.7% total return, according to Morningstar.com.

VWO’s one-year increase is substantial stronger vs. the second-best performer – US equities — over the past 12 months. Vanguard Total Stock Market (VTI) is currently reporting a 19.9% total return for the year through May 19.

The biggest loser in the one-year column is still foreign bonds in developed markets. Although BWX pared its losses after last week’s bounce, the ETF is still fractionally in the red, posting a 0.3% decline for the year through Friday.