One Wall Street analyst is souring on the stock. A Wall Street analyst is souring on United Parcel Service (UPS -2.96%), and the stock is losing ground on the news. Shares of UPS traded down 3% as of 1:15 p.m. ET after the stock was downgraded to underweight at Barclays. No way out of the slow lane UPS and other shipping companies have been stuck in neutral of late. Concerns about the economy have made large shipping customers cautious, creating soft demand and limiting pricing power. A new UPS labor deal h ...