Louis Rukeyser is the host of public television's "Wall Street Week." Every Friday night some 10 million would-be investors sit faithfully in front of their TV sets, pencils in hand, listening to the advice of his guests. Every Monday morning, when the market reopens, they call their brokers with buy orders based on the recommendations of his televised stock market gurus. And every week, according to Norman Fosbuck, they lose money.

Fosback, president of the Institute for Econometric Research, a Fort Lauderdale, Fla., investment firm and newsletter publisher, says he researched the results of "Wall Street Week" investment suggestions "because they are the most widely disseminated form of stock advice reaching the American public." Fosback's firm traced the performance of some 200 stocks recommended on the show over an 18-month period. His data showed that while recommended stocks soared an average of 2.1% on the Monday following the show, and edged a bit higher for two more weeks, in the six weeks that followed they lost all of the accumulated gains, falling an average of 3.2%.

"If you want to make money on 'Wall Street Week' recommendations, you can't do it by watching the show," Fosback reported. "It is almost impossible for the public to profit." But there may still be a way to make money from "Wall Street Week." Since guests are booked as much as six weeks in advance, savvy investors can find out or figure out what stocks the guest has been recommending to clients, then get in and take advantage of the Monday-morning surge.

"Wall Street Week" producer Rich Dubroff, while not disputing "the mathematical accuracy" of Fosback's report, charges that "the study distorts the fundamental purpose of the show, which is not to give short-term advice but to be a source of investment information so people can make up their own minds." Fosback, he says, is peddling sour grapes: "He just wanted to get on the show," and the study was his way of striking back after he was rebuffed. Host Rukeyser, quoted in Barron's, was equally deprecating, calling the report "shabby" and Fosback "a publicity hound."

Fosback remains unabashed and promises to continue to keep an eye on the results of the show's suggestions. "For some reason they think we were picking on them," he says. "I never had any desire to go on the show, and I certainly wouldn't go on now hearing all those things about me."