Stocks that moved substantially or traded heavily Thursday:
Under Armour Inc., up $1.96 to $21.67
The athletic apparel maker reported higher costs but still beat Wall Street's expectations for the first quarter.
Comcast Corp., up 80 cents to $39.59
The cable TV and entertainment company reported first-quarter earnings that were far higher than analysts had expected.
Union Pacific Corp., up $3.36 to $113.59
The railroad operator's first-quarter profit climbed 9 percent as the company hauled more freight, increased prices and worked to control costs.
American Airlines Group Inc., down $2.42 to $43.98
The airline said its earnings plunged 67 percent in the first quarter as higher costs offset higher revenue from airfares.
Southwest Airlines Co., down $1.19 to $55.75
The company reported a 32 percent drop in first-quarter earnings as it flew more passengers but took in less revenue on average from each one. Costs for labor and fuel also rose.
Paypal Holdings Inc., up $2.74 to $47.15
The digital payments company reported earnings that easily surpassed Wall Street's forecasts.
Cooper Tire & Rubber Co., down $4.25 to $39.15
The tire maker posted earnings and revenue that fell far short of what analysts were expecting.
ServiceNow Inc., up $3.41 to $94.33
The maker of automation software for businesses reported earnings and revenue that beat Wall Street's forecasts.