FORTUNE — Like many people, Charlie Tian loaded up on tech stocks in the ’90s. A scientist at Fujitsu, he thought he knew the sector. Then the market crash proved he didn’t. Tian, 43, figured there was a better way for small investors. He started reading Warren Buffett’s annual letters back to 1972 and thought, “If I select the stocks he already owns, my risk will be much smaller.” Tian launched Gurufocus.com, a website tracking the holdings of about 50 great investors, from Buffett to hedge funder David Tepper. More recently Tian has hired analysts and begun building stocks-election programs that emulate the investors. One screen is inspired by value legend Benjamin Graham; another by Buffett. In recent months the latter screen turned up Archer Daniels Midland (ADM), General Dynamics (GD), and McDonald’s (MCD). Tian’s work got an unintentional endorsement in July when Buffett told an interviewer that ADM and General Dynamics are the kinds of companies he’d consider buying.

This article is from the August 15, 2011 issue of Fortune.