Prior to Monday, it was safe to say natural gas futures and the relevant exchange traded products were enjoying banner starts to 2014.

Even with a 5.7% decline Monday, the United States Natural Gas Fund (NYSEArca: UNG) is still up more than 26% this year while the iPath Dow Jones-UBS Natural Gas Total Return Sub-Index ETN (NYSEArca: GAZ) is up more than 20%.[Some Investors Leaving Nat Gas ETFs]

The equity-based First Trust ISE-Revere Natural Gas Index Fund (NYSEArca: FCG) is struggling to keep pace and is up just 5.6% year-to-date.

“This is hardly what one would expect. While costs and other factors also have an important impact on producer profits, revenues are directly impacted by commodity prices. Due to operating leverage, an increase in gas prices should have a more than commensurate effect on the increase in a producer’s earnings. This effect can and will be muted by any hedging that producers may undertake. But the producers and the commodity should track each other both directionally and to some greater or lesser extent, proportionally,” writes Christopher Wallace in a post on Seeking Alpha.

Wallace notes that the “ratio of FCG to natural gas now sits at 3.3, over 60% below where it peaked at during 2012 and some 43% below the 4-year average for that ratio,” a scenario that could imply upside ahead for the $479.4 million FCG.