U.S. stocks flitted between minor losses and gains to end narrowly mixed on the final day of the shortened trading week. Crude oil closed out the day with another big gain, recapturing a level close to $38 a barrel. Cal-Maine Foods (CALM) clawed back into positive territory by the close of Thursday's trading. Shares of the egg producer had been under pressure after profit and sales estimates missed forecasts. Expectations had been high as egg prices surged after a bird flu outbreak. Hyatt Hotels (H) fell after disclosing that its payment processing system had been infected with malware. The hotel chain discovered the attack on November 30 and said the problem has since been fixed. Salesforce (CRM) dipped after the business software company agreed to buy SteelBrick for $360 million. TheStreet's Keris Lahiff has details from New York.