U.S. Markets started the new trading week on a positive note. Stocks advanced on hopes that geopolitical tensions are easing and on corporate deal news. A bidding war is brewing for Family Dollar Stores (FDO). Dollar General (DG) is now offering to buy the rival dollar store retailer in an all-cash deal. The bid tops Dollar Tree's (DLTR) offer for Family Dollar in July for about $8.5 billion. Telsa (TSLA) has expanded the warranty on its Model S electric car. Tesla is retroactively extending the same eight-year warranty as its battery pack with no mileage limit. Target (TGT) is planning to keep some of its stores open later to draw in more customers. The big box retailer will stay open until midnight at nearly 900 of its stores. TheStreet's Susannah Lee has details from New York.