Once the exclusively the realm of big brokerage houses, electronic trading eventually ended up in the hands of regular traders and investors.
The next stage of trading is already on the scene. It’s called high frequency trading (HFT), but it’s also described as algorithmic trading or quant trading. And that is a lot like Automated Trading.
An article in MIT’s Technology Review has a great profile about Tradeworx (the article is now archived for subscribers), one of the top quant trading firms. The firm and other quant funds are capable of making fortunes in milliseconds.