the device accounts for more than half of apple's quarterly revenue and its success is part of the reason why it's one of the best-performing stocks in the dow this year, up more than 25%, but even more stunning, since its launch apple has sold more than 1 billion iphones. christina alessi, cnn money, new york. with e*trade's powerful trading tools, right at your fingertips, you have access to in-depth analysis, level 2 data, and a team of experienced traders ready to help you if you need it. ♪ ♪ it's like having the power of a trading floor, wherever you are. it's your trade. ♪ ♪ e*trade. ♪ ♪