Earnings Just Got Serious for Buffett's Berkshire

NEW YORK (TheStreet) -- With earnings season getting into full swing, investors, analysts and market commentators will have their sights set on top companies as they continue to step up to the plate. Anticipation builds as banks and bellwethers release their most recent quarterly performance numbers and provide insight and guidance.

Billionaire Warren Buffett will surely be all ears. His investment empire Berkshire Hathaway (BRKA) is not found on the list for this coming week, but a number of the companies that make up its legendary stock portfolio are.

Warren Buffett

Intel (INTC) , Johnson & Johnson (JNJ) , Coca Cola (KO) and IBM (IBM) are among the firms slated to report on Tuesday, while American Express (AXP) is on the docket for Wednesday.

This quintet, along with Wells Fargo (WFC) , which joins JPMorgan (JMP) on the earnings stage Friday morning, is heavily influential in determining the day-to-day action seen from Warren Buffett's stock portfolio. At the start of the year, together they comprised nearly 70% of its assets. Coca-Cola, IBM, Wells Fargo and American Express alone represent a 65% slice.

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A strong showing from these names would be a welcomed relief for investors who have watched as Berkshire Hathaway has struggled to keep up with the broader S&P 500, in recent months. The firm's 3.5% return since the start of 2012 has been dwarfed by the S&P 500's, which has more than doubled this performance.

This underperformance extends beyond the past few months. Over the past year period, shares of Berkshire Hathaway are off nearly 4%. The benchmark average, meanwhile, has returned more than 3%.