As U.S. stocks have soared in 2013, one of last year’s most popular trends in the exchange traded funds world has taken some lumps. Low volatility ETFs, though not surprisingly, have lagged the S&P 500.

While the S&P 500 is up almost 27% year-to-date, the PowerShares S&P 500 Low Volatility Portfolio (NYSEArca: SPLV) and the iShares MSCI USA Minimum Volatility ETF (NYSEArca: USMV) are up an average of 20%. A possibly crowded trade and the second-quarter spike in interest rates due speculation of the Federal Reserve tapering its asset-buying program have hampered “low vol” ETFs this year. [Slack Utilities Stocks Weigh on Low Vol ETFs]

“The lower-volatility, more staid stocks these ETFs invest in can get downright sluggish — or, worse, excitable — if too many investors pile in,” reports Brendan Conway for Barron’s.

Conway also notes sector allocations in low vol ETFs made the fund vulnerable to “the midyear interest-rate scare.” SPLV is nearly 45% allocated to rate-sensitive utilities and staples stocks while staples, utilities and telecom stocks combine for about 28% of USMV’s weight.

To be fair to SPLV and USMV, both have generated positive returns this year and the composition of these funds would indicate the potential for laggard status in overt bull markets. Additionally, both ETFs have been inflow positive in 2013, confirming investors still have some appetite for damping volatility in their portfolios. [Low Volatility ETFs Remain Popular With Risk-Averse Investors]

And it should be noted that SPLV and USMV are far from the only popular ETFs that have been stung by rising rates. Several marquee dividend and REIT ETFs have also been hit by rising rates and in the case of REIT ETFs, some have generated negative returns since Treasury yields spiked starting the in the second quarter.