In the wake of the collapse of MF Global this fall, Wall Street has set its sights on Jefferies and its exposure to the risky sovereign debt of eurozone nations such as Italy. Led by CEO Richard Handler, New York-based Jefferies has fought back aggressively against rumors and negative analyst reports that have hammered its stock, which has plunged 55% so far this year. Buoyed by the better-than-expected results and efforts to strengthen its balance sheet, shares of Jefferies rallied more than 5% out of the gate on Tuesday.