The ECB's latest survey of the euro zone's money market said aggregate turnover in the unsecured-lending market, which Euribor tracks, was down 36% on the year in the second quarter of 2012.

WSJ: Third Bank Exits Euribor Panel

The European Commission can control mergers where the parties have an aggregate worldwide turnover exceeding 5 billion euro and at least two of the parties have a Community turnover exceeding 250 million euro.

BBC: Timetable of a merger

Aggregate ETF turnover in the U.S. exceeds turnover in stocks: in 2008, the average daily turnover of the five largest ETFs was three times as large as that of the largest stocks, according to NYSE Euronext.

FORBES: UBS' $2B Man, Kweku Adoboli, And The Perils Of ETFs