Take a look at some of Thursday's midday movers:
Barnes & Noble - The bookseller rose after saying it would join forces with Samsung to develop Nook tablets.
Costco Wholesale - The warehouse club advanced after posting a better-than-expected rise in same-store sales in May.
General Motors - The auto manufacturer gained a bit after CEO Mary Barra said 15 employees have been fired and five others disciplined for failing to disclose a defect with ignition switches linked to 13 deaths.
Navistar International - The truck and engine maker climbed after reporting a smaller quarterly loss.