Those of us old enough to have enjoyed the pop culture offerings of the 1980s may remember the Bananarama hit “Cruel Summer.” It reached number eight on the charts in the U.K. in 1983 and number nine in the U.S. a year later.

It has been anything but a cruel summer for silver exchange traded funds, such as the iShares Silver Trust (NYSEArca: SLV) and the ETFS Physical Silver Shares (NYSEArca: SIVR).

The price of silver has risen 10 percent since the end of May, more than double the gains in gold, bonds and stocks. This comes after a three-year slump when silver was down 50 percent, trailing gold by 30 percent and the S&P 500 Index by 100 percent,” writes Eric Balchunas for Bloomberg.

As has been the case for gold miners ETFs that have been buoyed by bullion’s rise, silver miners are enjoying the white metal’s surge. Since the end of May, the Global X Silvers Miners ETF (NYSEArca: SIL) is up nearly 26% while its small-cap rival, the PureFunds ISE Junior Silver Small Cap Miners/Explorers ETF (NYSEArca: SILJ), has surged 38.5%. [Big Shine for Small Silver Miners ETF]

The rally in silver that commenced in late May started among some of the lowest volatility for the metal seen in years.

“History indicates the recent decline in silver price volatility to the lowest levels in over a decade(at the beginning of May), as measured by 30-day volatility, may be a precursor to a strong price move. In our view, downside risk is limited with industrial demand picking up and supply in decline. With the silver price less than half its 2011 peak and futures shorts already elevated, we believe the next strong trend price move is likely to be up,” said ETF Securities on May 29.

Fundamentals are supportive of further upside for silver ETFs. “Silver is benefiting from a drop in total supply, a pickup in manufacturing and increased demand from China,” writes Balchunas.

Investors should also pay attention to the gold/silver ratio, the measurement of how many ounces of the white metal needed to purchase one ounce of its yellow counterpart. The ratio has been in rally mode since early June and if it breaks the multi-year resistance it is currently flirting with, that could portend added upside for both metals and the corresponding ETFs. [Important Clues From the Gold/Silver Ratio]

iShares Silver Trust

ETF Trends editorial team contributed to this post. Tom Lydon’s clients own shares of SLV.