Shares of Halliburton Co. /zigman2/quotes/210488727/composite HAL -3.21% swung to a gain of 5.2% in premarket trading Monday, reversing an earlier loss, after the oil services company reported a surprise second-quarter adjusted profit but revenue that fell short of expectations. The company swung to a net loss of $1.68 billion, or $1.91 share, from net income of $75 million, or 9 cents a share, in the year-ago period. Excluding non-recurring items, such as a $1.1 billion impairment and other charges to adjust costs with market conditions, adjusted earnings per share came to 5 cents, compared with the FactSet consensus for a per-share loss of 11 cents. Revenue fell 46% to $3.20 billion, below the FactSet consensus of $3.31 billion. Completion and production revenue dropped 56% to $1.67 billion, just below the FactSet consensus of $1.70 billion, and drilling and evaluation revenue fell 28% to $1.52 billion to miss expectations of $1.62 billion. North America revenue dropped 68% to $1.05 billion, just shy of expectations of $1.08 billion. The company said results were pressured by a decrease in pumping activity and drilling-related services. Halliburton's stock has tumbled 46.6% year to date through Friday, while the VanEck Vectors Oil Services ETF /zigman2/quotes/207596637/composite OIH -2.79% has lost 54.2% and the S&P 500 /zigman2/quotes/210599714/realtime SPX -1.31% has slipped 0.2%.