He said that if self-directed investors wanted to use a similar strategy, they should avoid pitfalls like rapid trading, which would result in rapidly mounting expenses.

Chaikin Power Tools were developed for self-directed investors in order to provide them with access to information generally available only to institutional investors.

By contrast, he said, Ameritrade will "stay intensely focused on the self-directed investor."

These people are "two-income families, very time pressed, self-directed investors who want information and to make their own decisions."

"Most of the users are self-directed investors and like to check how they are doing."

They are also self-directed investors who want to punish themselves: as a reality check, I nervously plugged in my own numbers.

"Our customers are self-directed investors, the type who will buy individual stocks and bonds," Mr. Trotter said.

Mr. Ivey described himself as the sort of self-directed investor that Schwab traditionally has served.

"We're providing general investment guidelines to help self-directed investors," he said.

It is a holding company, the major business of which is an online discount stock brokerage service for self-directed investors.