Check out the companies making headlines after the bell Monday:
Express Scripts' stock edged lower after the pharmacy-benefit management service posted lower-than-expected revenues in the first quarter. Express Scripts posted earnings of $1.22 per share, excluding items, in line with expectations, on revenues of $24.79 billion, below the $25.2 billion expected.
Shares of Sanmina popped in extended trading after the company's earnings per share hit a decade high in the latest quarter. The company, which manufacturers parts for electronic equipment, posted non-GAAP diluted earnings per share of 63 cents on revenue of $1.61 billion.
Canadian National Railway's stock fell after the company trimmed its 2016 financial outlook. After weaker-than-expected freight demand and currency headwinds, the transportation company now expects to report flat earnings per share this year, lower than January estimates that called for modest growth.
Shares of Pioneer Natural Resources bounced after reporting a narrower loss than expected in the first quarter. The independent oil-and-gas-exploration company posted a loss of 64 cents per share, adjusted for one-time costs. That's less than the 73 cents per share expected by Wall Street, according to the Associated Press.
Offshore oil rig contracting company Nabors Industries stumbled after reporting a loss of 29 cents per share in the first quarter, adjusted, according to the Associated Press. The company suffered lower operating cash flows as seasonal contracts failed to materialize in Canada, CEO Anthony Petrello said, in a statement.
"Our first-quarter results reflect the continued strain from low commodity prices. In particular, the first quarter's drop in oil prices below $30 led to sharp reductions in customer spending plans on a worldwide basis and had a corresponding adverse impact on our results,"Petrello said.