Check out the companies making headlines in after hours trading. Discover Financial Services — Shares rose 2.7% after Discover Financial Services reported results from its second quarter. The bank and payments company posted net interest income of $3.52 billion, topping the FactSet consensus estimate of $3.46 billion. Earnings came in at $6.06 per share, beating analysts’ estimates of $3.10 per share. Kinder Morgan — Shares dropped 2.8% after Kinder Morgan posted quarterly results that were below expectations. The pipeline operator reported second-quarter adjusted earnings of 25 cents per share, less than the 26 cents per share anticipated by analysts polled by FactSet. Revenue also missed expectations. United Airlines — The stock was down slightly, by 0.3% after United Airlines reported a mixed second quarter. The company posted second-quarter adjusted earnings of $4.14 per share, above the LSEG consensus estimate of $3.93 per share. However, revenue of $14.99 billion was below the expected $15.06 billion. Steel Dynamics — Shares of the steel producer advanced nearly 2%. Steel Dynamics posted second quarter earnings of $2.72 per share on revenue of $4.63 billion. Analysts polled by LSEG called for earnings of $2.67 per share and revenue of $4.43 billion. Alcoa — The aluminum company inched higher by 1.5%. Alcoa posted adjusted earnings of 16 cents per share, beating analysts’ forecast for 9 cents per share, per LSEG. Revenue also came in higher than anticipated at $2.91 billion, while analysts called for $2.84 billion. — CNBC’s Darla Mercado contributed reporting.