Nasdaq Stock Market

I:IXIC

rocketed 6%, after news that hedge fund manager Samuel Heyman has taken a 9% equity stake in the London Stock Exchange. The Nasdaq hopes to acquire the LSE, even after London officials rejected its $5.1 billion bid. Some see Heyman's move as an indication a deal is inevitable. But others say it could greatly increase the Nasdaq's purchase price, which might scuttle a deal and avoid any additional expenditure. Shares were up $2.63 to $40.95.

Friedman Billings Ramsey

(FBR)

rose after the firm announced that it had agreed to a $4.5 million settlement with

CompuDyne

( CDCY) and a William Blair-managed fund. CompuDyne had been feuding with Friedman Billings over its handling of a PIPE deal, or private investment in public equity. Shares were trading up 8 cents, or 1.1%, to $7.45.

LaBranche

( LAB) shares soared a day after federal prosecutors dropped criminal charges against five former specialists, who were accused of making improper trades in

New York Stock Exchange

-listed stocks. The decision by prosecutors to abandon the case is being seen by Wall Street as the elimination of one hurdle for the specialists firms, of which LaBranche is one of the largest. Shares rose $1.15, or 11%, to $11.85.

Education Realty Trust

(EDR)

dropped after Citigroup began coverage on the real estate investment trust with a sell rating. Shares were down 35 cents, or 2.2%, to $15.54.

Investment Technology Group

(ITG)

fell after the New York-based firm announced it was being sued by broker Liquidnet over alleged patent infringement relating to Liquidnet's indications-based trading systems. Shares were down 54 cents, or 1.4%, to $39.56.