Billionaire Warren Buffett encouraged investors to maintain their faith in America's economy and the businesses his Berkshire Hathaway conglomerate owns in a reassuring letter to his shareholders on February 27.

Buffett hardly even addressed the coronavirus that ravaged many businesses last year, instead focusing on the long-term prospects for the railroad, utility, and insurance businesses and stocks that belong to Berkshire Hathaway. But he said U.S. business will thrive over time in spite of the pandemic.

"In its brief 232 years of existence, however, there has been no incubator for unleashing human potential like America. Despite some severe interruptions, our country’s economic progress has been breathtaking," Buffett wrote.

Buffett's annual letter is always well read in the business world because of his remarkably successful track record and his knack for explaining complicated subjects in simple terms.

But he didn't offer much explanation for why Berkshire hasn't made a major acquisition in several years or discuss the company's recent major new investments in Verizon Communications and Chevron, leaving many investors wanting more.

"The one thing that caught my eye about the letter was sort of what it didn’t have," CFRA Research analyst Cathy Seifert said. "I think what was notable was the fact that given everything that’s gone on in this country from the pandemic to all the social unrest to the social inflation and climate change that’s impacting the insurance industry. It was striking to me that none of that was mentioned in the letter."

Buffett, a long-time Democrat, largely avoided politics in the letter but he did express faith in the future of the country.

"We retain our constitutional aspiration of becoming ‘a more perfect union.’ Progress on that front has been slow, uneven and often discouraging. We have, however, moved forward and will continue to do so. Our unwavering conclusion: Never bet against America," he said.

Buffett said Berkshire's $120 billion stake in Apple is one of its most valuable assets—rivaling its BNSF railroad and Berkshire's utility division—even though it owns only 5.4% of the iPhone maker, hinting at a long-term commitment to the Apple investment.

Buffett said one of his biggest investments last year was the $25 billion repurchase of Berkshire's own shares. But even after that and several multibillion-dollar stock market investments in the second half of last year, Berkshire still held $138.3 billion cash at the end of 2020. Edward Jones analyst Jim Shanahan said it's significant that Buffett is investing that much in his own stock.

In addition to the letter, Berkshire said its fourth-quarter profits grew 23% to $35.8 billion, or $23,015 per Class A share, even though the pandemic continued to weigh on most of its businesses, which include BNSF railroad, several major utilities, Geico insurance, and an assortment of manufacturers and retailers. Most of the gain over last year’s $29.2 billion, or $17,909 per A share, was related to paper gains on the value of its investments.

Buffett maintains that Berkshire’s operating earnings offer a better view of quarterly performance because they exclude investments and derivatives, which can vary widely. By that measure, Berkshire’s operating earnings increased by nearly 14%, to $5.02 billion, or $3,224.74 per Class A share. That’s up from $4.42 billion, or $2,714.76 per Class A share, a year earlier.

The four analysts surveyed by FactSet expected Berkshire to report quarterly operating earnings per Class A share of $3,413.01.

One of Berkshire's hardest-hit businesses last year was aviation parts manufacturer Precision Castparts, which lost a significant amount of business because airlines struggled due to the pandemic. Buffett, who took a nearly $10 billion writedown on the value of Precision Castparts last year, said he made a mistake when he agreed to pay $32.3 billion for that business.

"No one misled me in any way—I was simply too optimistic about PCC’s normalized profit potential," Buffett said. "Last year, my miscalculation was laid bare by adverse developments throughout the aerospace industry, PCC’s most important source of customers."

Besides the business lessons Buffett offered in his missive, the 90-year-old investor reassured his stockholders that he has no plans to retire; he said one of Berkshire’s most-experienced managers had retired at the "ridiculously premature retirement age" of 103.

In a break from tradition, this year's annual meeting will be broadcast from Los Angeles instead of Omaha in May, Buffett said. He will be reunited on stage with his investing partner, Charlie Munger, who missed last year's virtual meeting. Berkshire's other vice chairmen—Greg Abel and Ajit Jain—will also be there to respond during the 3.5-hour-long question period. Abel and Jain are both viewed as potential successors to Buffett as CEO, and since 2018, Jain has overseen all of Berkshire’s insurance businesses while Abel has overseen the conglomerate’s non-insurance operations.