Last week, five of the 10 biggest stocks in Warren Buffett's Berkshire Hathaway (NYSE:BRK-A) (NYSE:BRK-B) portfolio reported their third-quarter earnings, and investors are clamoring to know how he's feeling this week.

At the end of the second quarter, Berkshire Hathaway had a little more than $75 billion dollars invested in its 10 biggest stock holdings, which are broken out in the chart below:

Source: SEC filings.

So far we've seen Wells Fargo, Coca Cola (NYSE:KO), IBM (NYSE:IBM), American Express, and U.S. Bancorp (NYSE:USB), which represented $62 billion of his portfolio, all report earnings -- and while four of those companies had strong results, one of them dragged down the whole ship. Yet Warren Buffet's opinion on that company may surprise you.

Happy Warren. Image: Aaron Friedman.

Wells Fargo
Wells Fargo reported earnings on Friday, Oct. 11, and the stock shot down almost 2.5% after the news was reported -- even though the company reported its 10th straight quarter of record net income. While its income fell in large part to dwindling mortgage refinancings, it still saw strong growth in its other business lines. It also improved its ever-important return on equity (which is what Buffett holds, after all!) from 13.4% to 14.1% over the past year. Despite the early dip, Wells Fargo's stock has rebounded nicely, and this bank looks poised to continue its strong performance -- which likely makes Buffett very happy.

Coca Cola
Thanks in large part to currency changes and one-time charges, Coke saw its revenue and net income drop in the third quarter. But if you exclude those, it actually saw its income grow by 8% and revenue grow by 4% in the quarter. While the company has still seen difficulty in its soft drink sales, it has seen strong growth in its tea business. Coke didn't blow its earnings out of the bottle, but it still had another solid quarter.

Warren Buffet once said about Coca-Cola, "I'm the kind of guy who likes to bet on sure things. No business has ever failed with happy customers ... and you're selling happiness." And while the packaging may be different from soda to tea, Coke is still selling happiness abundantly.

In November 2011, when Buffett disclosed his position in IBM on CNBC, he said about the management at IBM that "they treat their stock with reverence, which I find is unusual among big companies. Or they really -- they are thinking about the shareholder."

While IBM reported higher net income, as a result of weakening sales in China, IBM's revenue took a turn for the worse, and the stock plummeted as a result, falling almost 6%. So, is Warren Buffett now reevaluating his position in this tech giant?

I would suggest he isn't, as he also highlighted that one of the reason he liked IBM was that it articulates its vision and executes on it. CEO Ginni Rometty noted the company is "taking action to improve execution in our growth markets unit and in the elements of our hardware businesses that are under performing," which suggests the company has a clear plan to turn its poor performance in its struggling areas around, while also devoting resources to the businesses where it could grow.

American Express
On the other side of the IBM performance was American Express, which saw its stock rise over 5% after it reported earnings-per-share growth of 15%. It saw gains in revenue and income and even bought back 6% of its shares. Given that Warren Buffet first bought American Express in 1964 -- no one quarter would likely make him reevaluate his position in this company, but considering the loss in IBM was almost netted out by the gain in American Express, he is likely pretty thrilled with the strong performance by this card giant.

U.S. Bancorp
Lastly, there's U.S. Bancorp -- one of the more unheralded companies in Buffet's portfolio. Although it's the 10th largest bank in the United States with over $350 billion in assets, it certainly doesn't have the cachet of some of the other names on this list. Yet this bank, too, reported another strong quarter and was largely immune to some of the mortgage banking and fixed income trading issues that plagued other large banks. The bank continued to deliver excellent results, and once more paced industry in its profitability metrics of return on both average assets and equity. While it didn't blow the door off the hinges, this was another solid quarter for Buffett's seventh largest investment.

This quarter once more showed that Buffett's eye for investments in companies that produce consistently strong results in often unspectacular ways. While there were difficulties at IBM, they likely aren't anything that will concern Buffett and his investment thesis in the company. All things considered, Warren Buffett is likely pretty happy with how his investments are performing so far -- we'll see if that continues when Procter & Gamble reports this Friday -- but knowing Buffett's track record, it likely will.