Wal-Mart Stores and American Express shares didn't move much after they announced a reloadable prepaid card with no recurring or overdraft fees. But the news hammered shares of prepaid card competitor Green Dot Corp., which has also offered a card with Wal-Mart. Green Dot fell $2.57, or 20 percent, to $10.28.
UnitedHealth Group rose 41 cents to $57.54 after the health insurer said it would pay $4.9 billion in cash to buy most of Brazilian health benefits and hospital services provider Amil Participacoes.
Truck and engine maker Navistar rose $1.70, or 8 percent, to $22.91 after saying it will add two board members associated with activist investors, heading off a proxy battle.
European markets were also lower. The CAC-40 in France fell 1.5 percent, the FTSE 100 in Britain was down 0.5 percent, and the German DAX was down 1.4 percent.
U.S. government bond trading was closed for the Columbus Day holiday.