President Barack Obama hosts world leaders this weekend at a pair of summits that represent the first test of how upheavals among major economies stand to influence global policies on issues from the Afghanistan war to national budgets.

A plan by the Chicago exchange company to allow nearly round-the-clock electronic trading on its Chicago Board of Trade is drawing fire from brokers, farmers and floor traders.

Facebook priced its initial public offering at $38 a share, a move that values the Internet company at more than $100 billion. It tried floating higher numbers to investors but was rebuffed.