Full-screen option chains include sortable puts/calls columns, volume/open interest histograms and a put/call ratio indicating bullish or bearish trends.

"We are committed to evolving our mobile apps to meet or exceed the increasingly sophisticated needs of our mobile users," said Richard Blunck, executive vice president, digital distribution at Fidelity. "Mobile trading has quickly become a necessary tool for many of our active investors, so it's natural that we give them trading capabilities on the go that they're used to having on their desktops. In these fast-paced, volatile markets, mobile trading features can help give investors an edge."

In the past year, the number of mobile trades customers placed with Fidelity grew more than 90 percent. In addition to Fidelity's updated iPad app, investors can research and trade stocks, options, ETFs and mutual funds through the Fidelity Investments App for iPhone and iPod touch, and through its Android app and Fidelity Mobile for other smartphones such as BlackBerry.

Investors can download the Fidelity iPad app for no charge from the App Store on iPad or at iTunes.com. Current users can receive the new features by simply updating their existing Fidelity iPad App.

Fidelity Investments is one of the world's largest providers of financial services, with assets under administration of $3.5 trillion, including managed assets of $1.6 trillion, as of May 31, 2012.