Smith Barney Fires 4 Over Rapid Trading

Citigroup Inc.’s Smith Barney fired four brokers Thursday for rapid trading of mutual fund shares as state regulators said they might file more charges against firms and investors involved in improper transactions.

Smith Barney made the dismissals for “inappropriate behavior related to market timing” of mutual funds, said spokeswoman Susan Thomson, who wouldn’t name the brokers. Market timing occurs when investors try to exploit anticipated changes in share prices by buying and selling shares within a day.