MasterCard posted higher-than-expected quarterly earnings Thursday, but spending volume growth in the United States was weak and investors punished the credit and debit card network's shares.

Stocks plunged at the open as the morning's economic news disappointed: Economic growth was weaker than expected -- even with the boost of the rebate checks -- and jobless claims shot up to their highest level in five years.

To give investors an edge in this volatile market environment, CNBC asked the experts for their best trades now. 

By anyone's reckoning, it was a rough week.  Crude oil continued its relentless climb; banks and brokerages gave hints of more discouraging news; government data pointed to a weak economy; even strong companies like Nike, Oracle, and Research In Motion issued cautious guidance; and Federal Reserve policymakers, widely perceived as powerless to help, left interest rates unchanged.  But all week, even through the worst of the market's sell-offs, CNBC guests offered

MasterCard, the world's second-largest credit-card network, said it will pay American Express up to $1.8 billion to settle a lawsuit that said MasterCard and Visa blocked banks from issuing cards from their rival.

Stocks finished mixed amid volatile oil prices and a weak manufacturing report from the Fed.

U.S. retail gasoline demand slipped 3.8 percent from last year's levels, as gasoline prices posted yet another record high last week, MasterCard Advisors said Tuesday.

Consumer spending on apparel and footwear slid during May as buyers scaled back on discretionary purchases amid a sluggish U.S. economic environment, according to a SpendingPulse report released on Wednesday.