U.S. stock futures were trading lower on Wednesday as investors focused on several companies reporting earnings. Mercury Systems shares fell 12.3% to $92.09 in after-hours trading after the company reported fourth-quarter earnings of 37 cents per share, below the 38-cent analyst consensus, while sales of $289.782 million exceeded expectations of $266.403 million. Keysight Technologies gained 2.7% to $350.20 after reporting adjusted third-quarter earnings of $3.07 per share and revenue of $1.85 billion, beating estimates of $2.48 and $1.74 billion, respectively, and issuing strong fourth-quarter guidance. Lowe’s, Target and TJX Companies were expected to report before the market opened, with projected earnings of $4.23, $2.32 and $1.19 per share, respectively.