Sears Holdings Corp. fell a day after the retailer said chairman and hedge fund billionaire Edward Lampert will be CEO — even as the company offered an update on holiday sales that showed some improvement at Sears stores. Still, the company faces a long battle to turn itself around. Lampert succeeds Louis D’Ambrosio, who is leaving because of family health matters. Lampert has been known as a hands-on chairman at the chain, which has posted six straight years of sales declines.