Valero Energy beats Wall Street expectations in Q4 thanks to low costs. Find out why VLO stock is a buy as margins improve with competitors exiting the market.

Valero Energy on Thursday reported a sharp drop in refining profit and margins for the fourth quarter but still beat analyst estimates.

This was the stock's second consecutive day of losses.

Valero Energy Corporation (NYSE:VLO) reported a fourth-quarter sales decline of 13.2% year-on-year to $30.76 billion, beating the analyst consensus estimate of $30.20 billion. The Refining segment posted an operating income of $437 million,

Refiner Valero Energy beat fourth-quarter profit and revenue estimates on Thursday, helped by lower costs and steady output. Shares of the company rose 1.4% in premarket trading after the company also said profits doubled in its renewable diesel division and costs fell 10.