Online broker

Ameritrade

(AMTD) - Get Report

was down 0.4% in midafternoon after its founder and CEO, Joe Ricketts, said that the company is not for sale, even at $20, more than double the company's current price.

The company today also said it would offer two new brands, one targeting active traders and one serving those who want more service.

Rival Internet brokerage

E*Trade Group

(ET) - Get Report

was down 2.7%.