Stocks had yo-yoed from minor gains to a sharp drop and back again by midday Tuesday. Markets were choppy on a mixed bag of earnings and as the Federal Reserve kicked off a two-day policy meeting. Consumer confidence in April dropped unexpectedly to its lowest level since December due to recent softness in the labor market. UPS (UPS) was giving the S&P 500 a boost as profit beat estimates and total shipment volume over its first quarter increased nearly 3%. Coach (COH) was a drag, though, after sales in North America plummeted 24%. Overall revenue tanked nearly 16% with only a portion attributable to foreign exchange.