The United States Oil Fund (NYSEArca: USO), which tracks West Texas Intermediate crude oil futures, and the United States Brent Oil Fund (NYSEArca: BNO), which tracks Brent crude oil futures, were among the best-performing commodities exchange traded products in the first half of 2018, but after some big gains, oil could face challenges.

Concerns over rising supply, notably out of the Organization of Petroleum Exporting Countries, put a damper on recent gains. Recently, Saudi Arabia stated its willingness to use spare production capacity to raise global supply. President Donald Trump has already called on foreign producers to raise supply to help curb rising prices.

“Goldman Sachs last week once again took the opportunity to espouse its bullish view on black gold. The investment bank thinks ‘the dollar will likely weaken from here,’ and said any impact from Chinese tariffs on U.S. crude exports will be quickly absorbed by the market,” according to Schaeffer’s Investment Research.

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Since 2016, OPEC and a number of other major oil prices like Russia have been in a concerted effort to cut 2% of the global crude supply in an attempt to diminish the global supply glut and stabilize crude prices. Analysts now project the oil market could move into a deficit in the second part of 2018 and 2019 of 0.5 million barrels and later 0.3 million barrels per day as demand begins to outpace supply.

“With crude oil having gained in the neighborhood of 66% over the last 52 weeks, data from Schaeffer’s Senior Quantitative Analyst Chris Prybal throws some cold water on the bull case for oil. Looking back to 1978, Prybal found that in the 35 instances where crude oil was up by 50% or more on a year-over-year (YoY) basis, the commodity went on to underperform its historical average returns,” reports Schaeffer’s.

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Asia could provide a supporting pillar for the energy market as demand among Asian economies is expected to surpass $1 trillion this year, or twice as much as in 2015 and 2016. Asia-Pacific consumers consumes over 35% of the 100 million barrels of oil the world uses per day and the percentage is only rising, Reuters reports.

“While the price action in the commodity has hardly broken down as of yet, it seems fair to say that quite a few of the fundamental concerns that have lately supported oil have been largely priced in, which could set the stage for a steady cooldown over the longer haul,” adds Schaeffer’s.

For more information on the oil market, visit our energy category.