Bear Stearns sahres surged Thursday as the company posted an 81% gain in second-quarter earnings. The company earned $539 million, or $3.72 a share, up from $298 million, or $2.09 a share, in the year-ago period. The firm generated net revenue of $2.5 billion in the quarter, up 33% from a year ago. The New York-based brokerage blew past the Thomson Financial consensus estimate for earnings of $3.12 a share on revenue of $2.1 billion. Shares gained $7.03, or 5.7%, to $131.23 in recent trading. GFI Group ( GFIG) surged after the New York-based brokerage was upgraded by Citigroup to buy from hold. Shares gained $5.81, or 12.5%, to $52.44 in recent trading. CharterMac ( CHC) gained after the New York-based real estate finance company said it agreed to acquire 100% of the ownership interests of ARCap Investors, a privately-held Dallas-based fund manager, in a deal that values ARCap at $284.5 million. "The acquisition of ARCap is the next step in the transformation of our company from a spread investor to a real estate fund manager," CharterMac CEO Marc Schnitzer said in a statement. Shares climbed 42 cents, or 2.5%, to $17.45 in recent trading. Thornburg Mortgage gained after the Santa Fe, N.M.-based single-family residential mortgage lending company declared a second-quarter dividend of 50 cents a share on its 8% Series C cumulative redeemable preferred stock. This dividend will be payable on July 17 to preferred shareholders of record as of June 30. The ex-dividend date is June 28. Shares gained 73 cents, or 2.8%, to $26.69 recently.