Berkshire Hathaway Inc. shares traded near record highs at the beginning of Warren Buffett’s 50th year running the company. More recently, the stock has begun to sag.

Shares have slumped 5.2 percent since Dec. 31 and are headed for their first annual decline since 2011, even as Buffett pulled off one of the biggest coups of his career last month. By backing H.J. Heinz’s merger with Kraft Foods Group Inc., he now holds a stake valued at about $26 billion, more than twice what he paid.

There’s less to celebrate about some other Berkshire investments and businesses. Buffett’s railroad has had to spend heavily to come back from service delays in 2014. His reinsurance business, a main source of funding for the company, is facing increased competition. And some of his biggest equity investments -- like International Business Machines Corp. and American Express Co. -- have lagged the market.

“We’re talking about a large, diversified portfolio of companies,” said Jim Shanahan, an analyst at Edward Jones. “Some will underperform and some will outperform.”

Over the past five decades, Buffett has built Berkshire into a sprawling operation and amassed one of the best investing records in history. Through 2014, the company’s share price averaged annual gains that were more than double the Standard & Poor’s 500 Index. The equity benchmark is up 1.7 percent this year.

Berkshire’s dozens of subsidiaries include insurers, manufacturers, retailers, electric utilities and the railroad, BNSF. Buffett also oversees a stock portfolio valued at more than $100 billion.

Earnings Outlook

The diversity of those investments could help the company post operating earnings per share of $3,038 when results are released on Friday, according to the estimates of three analysts surveyed by Bloomberg. That’s a 15 percent increase from a year earlier.

Buffett’s favored yardstick -- book value -- could have risen by about 2 percent to around $150,000 a share during the second quarter, according to an estimate from Cliff Gallant, an analyst at Nomura Holdings Inc. The billionaire Berkshire chairman and chief executive officer has said the metric is a good, though understated, proxy for the company’s true worth. Berkshire’s Class A shares closed at $214,150 on Tuesday.

Book value per share will get a boost in the current quarter as Berkshire records a gain on the bet on Kraft and Heinz, said Gallant. The food companies completed their merger in July to create Kraft Heinz Co.