After from the Fed rate hike speculation, an oil rally was the most talked-about topic in recent times. This is because the liquid commodity staged the greatest rally in seven years, crossing the $50 mark on May 26, 2016. This was also a major jump from the below-$30 level hit in February.

WTI crude ETF United States Oil Fund (USO) added about 36.1% in the last three months (as of May 26, 2016) while Brent crude oil ETF United States Brent Oil Fund(BNO) returned about 36.9%.

The commodity has been sliding since mid-2014 mainly on rising supplies and falling demand. Constant global growth worries pushed oil down to levels not seen in a very long time. However, things started to turn around lately. Hopes of easing supply glut and signs of stabilization in various economies including the U.S. and China pushed oil prices up to the seven-month high.

The curb in supplies mainly emanated from production disruption in Canada due to the Alberta wildfires, militant attacks and the threat of a nationwide strike in Nigeria, the political rout in Venezuela, and reduced shale production in the U.S.
The Energy Information Administration (EIA) now expects shale output to decline by113,000 barrels a day in June from May. Weekly drawdown reports of U.S. crude stockpiles also point to sustained demand and dwindling supplies (read: Alberta Wildfire Puts These ETFs in Focus).

If this was not enough, Goldman Sachs – a candidate with bearish sentiments on oil for long – recently turned bullish on the commodity. Goldman’s bullishness on oil acted gave a considerable boost to the space.

Though the recent gains may ease out if the greenback continues to strengthen on a possible Fed hike, investors must be interested in knowing which energy ETFs made the most of the recent rally (read: Oil to Hit $50? Buy These Country ETFs).

While most of energy funds and the asset classes directly related oil raked in gains in the last five trading days (as of May 26, 2016), below we  highlight a few top-performing oil and gas equipment and services ETFs that led the energy ETFs pack higher.

SPDR S&P Oil & Gas Equipment & Services ETF (XES)

This fund provides exposure across 35 securities by tracking the S&P Oil & Gas Equipment & Services Select Industry Index. None of the firms accounts for more than 4.99% of total assets. The fund has amassed $213.3 million in its asset base. The ETF has an expense ratio of 0.35% (read: 4 Energy ETFs Outperforming on Oil Rebound).

Shares US Oil Equipment & Services ETF (IEZ)

This ETF – tracking the Dow Jones U.S. Select Oil Equipment & Services Index – invests about $239.2 million of assets in 39 securities, focusing solely on the energy world. The fund has significant company-specific concentration risks. Schlumberger Takes up the first position here with 19.93% of holdings while Halliburton takes up the second position with about 10.72% of total assets. IEZ charges 0.45% for its expense ratio (see all energy ETFs here).

Market Vectors Oil Services ETF (OIH)

OIH invests about $926.7 million of assets in 26 holdings. The fund devotes as much as 21.2% weight to Schlumberger, indicating high company-specific concentration risks. Halliburton takes about 15.65% of the fund. The net expense ratio of the fund is 0.35%.