“People read and subscribe to the newsletter because they subscribe to the philosophy of investing versus trading, earning long-term gains that compound on themselves, staying the course and, yes, finding the best active managers at a shop that markets indexing over all else,” Mr. Wiener said. Among the 30,000 to 40,000 subscribers, he said, are some with portfolios in the high seven digits.

Mr. Wiener and his co-editor, Jeff DeMaso, often remind subscribers that they invest their own money in the same funds they recommend. Mr. Wiener is also the chairman of Adviser Investments, an investment advisory firm in Newton, Mass., with $6 billion under management. He said the firm’s 401(k) options for its own employees comprise some of the same funds the newsletter recommends.

Mr. Wiener’s tenure at the helm of the newsletter hasn’t been free of friction with the company he covers: In 1993, Vanguard sued the newsletter for trademark infringement in a case that was settled.

A print newsletter appeals to investors like Tom Yoder, 76, who said he had subscribed to the Morningstar FundInvestor since 2004 and reads it from “cover to cover,” taking notes in the margins.

Russel Kinnel, the editor of Morningstar FundInvestor, which was first published in 1992, said the majority of the 20,000 subscribers were older investors who received the print edition for $165 a year. “It is very heavily do-it-yourselfers,” he said. “In many cases, they came to us after being burned by brokers who turned out to be salespeople rather than investors.”

Mr. Yoder, who lives in Dallas and retired six years ago from Fannie Mae, said he self-manages eight no-load equity mutual funds in his I.R.A. to avoid an annual fee or other sales charges. He keeps enough cash to cover three to four years of expenses in his taxable accounts as a counterweight. Because of his equity focus, Mr. Yoder said, his choices are “critically important.” He relies on the Morningstar newsletter to “keep me alert to fund and market changes.”

Morningstar FundInvestor, which is owned by the global financial services company Morningstar, has 500 mutual funds to choose from and evaluates these funds with both its forward-looking analyst or “medalist” ratings and its star ratings based on past performance. The newsletter has 40 Morningstar analysts serving as rotating authors. Mr. Kinnel said he also invested his own money in medalist funds and in the managers and funds he recommends.