OMAHA, Neb. — Billionaire Warren Buffett used his much anticipated annual letter to Berkshire Hathaway shareholders to reiterate his wariness of high Wall Street fees and his positive outlook for the U.S. economy.

Buffett devoted a section of the letter released Saturday to again explain the benefits low-cost index funds have over most other investments. But he kept the letter focused on business and didn’t weigh in on politics.

He said he estimates that wealthy investors who use high-priced advisers have wasted over $100 billion over the past decade.

“The bottom line: When trillions of dollars are managed by Wall Streeters charging high fees, it will usually be the managers who reap outsized profits, not the clients,” Buffett wrote. “Both large and small investors should stick with low-cost index funds.”

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To prove his point, Buffett recounted the first nine years of a 10-year bet he made that an S&P 500 index fund will outperform a collection of hedge funds. He made the wager with the money managers who own Protege Partners LLC a few months before the recession began in 2008 with both sides picking a charity that would get at least $1 million.

Buffett’s chosen index fund has recorded an 85.4 percent gain over than time while the hedge funds delivered an average of 22 percent.

Buffett again praised the country’s market system for its ability to allow Americans to continue building “mind-boggling amounts” of wealth, but he didn’t compare his views to dire picture political candidates offer, as he did a year ago. Buffett is a longtime Democrat who supported Hillary Clinton, but he has said he thinks the economy will be OK under President Donald Trump.

“I’ll repeat what I’ve both said in the past and expect to say in future years: Babies born in America today are the luckiest crop in history,” he said.

Buffett devoted most of his letter to detailing the evolution of Berkshire and the performance of the Omaha, Nebraska-based company last year. His annual letters are always well read because of his successful track record and his knack for explaining complicated subjects in simple terms.

Berkshire has come to rely increasingly more on acquisitions of entire operating businesses instead of just its stock portfolio that includes major stakes in Coca-Cola, Wells Fargo, Apple and others.

Berkshire already owns more than 90 subsidiaries, including Geico insurance, Berkshire Hathaway Energy, BNSF railroad, clothing, furniture and jewelry firms.

Buffett said he will continue looking for more acquisitions with Berkshire’s roughly $86 billion in cash, but the company’s size means it will be hard to match its previous results.

Buffett said Saturday that Berkshire recorded a 10.7 percent increase in book value and a 23.4 percent gain in stock price in 2016. Over the past 52 years, Berkshire’s book value — which is an estimate of its assets minus liabilities — improved 19 percent and its stock price grew 20.8 percent in compounded annual gains.