CNNMoney Resilient U.S. oil companies start pumping againCNNMoneyDespite OPEC's strategy of flooding the oversupplied market with tons of crude, American oil production has not fallen off a cliff. And now that prices have rallied back to $50 a barrel, there are early signs that U.S. shale is on the rebound, too …No change in North Dakota rig countUPI.comOil Fears Mount As Rig Count Rises... 

Reuters California regulator approves Aetna-Humana deal with conditionsReutersNEW YORK/WASHINGTON The California Department of Managed Health Care approved Aetna Inc's (AET.N) acquisition of Humana Inc (HUM.N) with conditions including the insurer's commitment to keeping premium increases at a minimum in the small …California Regulator Approves Aetna-Humana DealHartford Courant all... 

Wall Street Journal Volkswagen's Ex-CEO Martin Winterkorn Faces Probe Over Emissions ScandalWall Street JournalFRANKFURT—German prosecutors on Monday opened an investigation of former Volkswagen AG VLKAY 5.45 % chief executive Martin Winterkorn and an undisclosed person for allegedly not informing investors about potential losses in connection with the …Martin Winterkorn, Ex-CEO... 

CBS News ​Costco flips the switch to VisaCBS NewsBy Gregory Karp/NerdWallet. A longtime checkout-line hassle for many Costco shoppers ended Monday, when the wholesale club flipped the switch on its new credit card policy. It stopped accepting American Express and started taking only Visa — a …Shopping at Costco? Remember to switch your cardsChicago TribuneCostco switches credit cards... 

Wall Street Journal Wal-Mart Strikes Deal to Sell Chinese E-Commerce Business to JD.comWall Street JournalWal-Mart Stores Inc. WMT 0.28 % intends to sell its online e-commerce marketplace in China to the country's No. 2 e-commerce company as part of a strategic tie-up, the companies said. JD.com Inc., JD 6.31 % which is the second-largest online retailer …Walmart buys stake in Chinese...