While Mint aims at offering a quick, one-stop shop for investment and personal-spending information, Cake provides a more in-depth view of investments only. It is also focused strongly on the social aspect of investing, which, says CEO Steven Carpenter, is inherently social anyway. "We're already social with investing. There are investment clubs, and we talk about it at cocktail parties," he says. Cake is aiming to be the Facebook of investments, by letting customers create social networks of people who share investment interests, track others' progress, and compare the specifics of their investment decisions. "You want to know how you're doing compared to other people, and how they got there," Carpenter says. "You want to know if you own a bunch of stocks that other people are selling."

Unlike Mint, Cake built its own data aggregation platform, so it doesn't use a third party like Yodlee. Instead, Cake's software logs in to a brokerage firm's site on behalf of the user and collects information by scanning Web pages. This allows the company to gather more-specific bits of information, says Carpenter, and to access more than 10 years of historical investment data. Once Cake has that information, it runs it through algorithms that calculate investment efficiency and ranks the user compared with other Cake customers. The user then has the ability to review the investment strategies of higher-ranked customers.

Both Mint and Cake are providing an important alternative to brokerage firms that manage investments and charge a fee, Carpenter says. "With both Mint and Cake," he says, "we don't want you to move your assets to work with us."

Fidelity's Jenvey sees Web-based financial tools like Cake and Mint as moving the industry forward. He says that if the social aspects of money management and the commitment to transparency are adopted by the industry at large, it will "benefit the investor and household, and ultimately cause evolution within the industry."