The United States Oil Fund (NYSEArca: USO), which tracks West Texas Intermediate crude oil futures, is up nearly 10% over the past three months, but that does not mean issues that plagued energy stocks and exchange traded funds last year have evaporated.

Nor is oil’s recent upside a guarantee of gains for energy equities. While USO up almost 10% over the past three months, the Energy Select Sector SPDR (NYSEArca: XLE) is lower by 1.6% over the same period. Energy stocks often prove less bad than oil futures when the latter decline, but the rub with that scenario is that oil’s rebound does not equal dollar-for-dollar gains in energy equities. Other factors are continue hampering energy ETFs. [Oil’s Rise Doesn’t Guarantee the Same for Energy Stocks]

In a recent research note, S&P Capital IQ points out that inventories of natural gas liquids (NGLs) remain elevated and that is a thorn in the side of oil and natural gas exploration and production companies.

“Given the ongoing growth in supply, our view that prices will remain under pressure for all key hydrocarbons (crude oil, wet gas, and dry gas), and the expectation that exports will save the day, we are not optimistic on any kind of near-term recovery in NGL pricing. The next question becomes: how influential is NGL pricing on E&P production?,” according to the research firm.

S&P Capital is less-than-enthusiastic on stocks with NGL exposure, including Cimarex Energy (NYSE: XEC), Devon Energy (NYSE: DVN) and Pioneer Natural Resources (NYSE: PXD). The research firm has tepid two-star ratings on all three of those names, which combine for 9.2% of the iShares U.S. Oil & Gas Exploration & Production ETF (NYSEArca: IEO).

The $458.6 million IEO is down 2.3% over the past 90 days. IEO allocates about 28% of its combined weight to ConocoPhillips (NYSE: COP), EOG Resources (NYSE: EOG) and Phillips 66 (NYSE: PSX). [Exploration and Production ETFs Stung by Glum Wall Street Views]