Citigroup Inc. announced that it has agreed to buy Automated Trading Desk $680 million, including more than $102 million in cash. Automated Trading Desk is a Mount Pleasant, S.C.-based developer of automated trading and customized equity execution solutions. The company raised $60 million in equity earlier this year from Technology Crossover Ventures. Founded in 1988, Automated Trading Desk has about 120 broker-dealer customers and trades, on average, more than 200 million shares daily, which is about 6% of the volume of the New York Stock Exchange and Nasdaq combined. http://www.citigroup.com