southwest airlines stock slipped in premarket trading after the carrier canceled more than 1800 flights over the weekend and the problems spilled over into monday the dallasbased airline ticker luv canceled more than 1100 flights on sunday alone or 30 of its schedule according to data from flight tracker flightaware the problems continued into monday with a further 348 flights canceled as of 730 am et the airline’s stock was 3 lower ahead of the open