Benzinga's Volume Movers

Alterra Capital Holdings

shares moved up 23.22% to $28.52 at 10:29 am. The volume of Alterra Capital shares traded was 3116% higher than normal. Markel

announced its plans to buy Alterra Capital Holdings for around $3 billion. General Motors Company

shares climbed 5.77% to $26.96. The volume of General Motors shares traded was 634% higher than normal. The US Treasury announced its plans to sell its remaining stake of around 300.1 million in General Motors. Vipshop Holdings

shares gained 4.59% to $15.22. The volume of Vipshop shares traded was 541% higher than normal. Vipshop's trailing-twelve-month revenue is $497.69 million. Delphi Automotive PLC

shares rose 2.37% to $35.26. The volume of Delphi Automotive shares traded was 379% higher than normal. Delphi Automotive will replace Titanium Metals

in the S&P 500 index after the close of trading on December 21.