Fueled by an big increase for its insurance underwriting businesses, Warren Buffett's Berkshire Hathaway reported first-quarter operating earnings soared to $3.8 billion, a 42-percent increase from the same period last year.

Berkshire's insurance underwriting profits jumped to $901 million, more than 16 times the $54 million it recorded a year ago.

The company's non-insurance businesses generated a more modest earnings increase of 12 percent to $2.25 billion.

Events in Europe are a great example of bankers gone wild and you simply can't trust them, said Warren Buffett's right-hand man Charlie Munger.

"What Cyprus demonstrates is an old truth: You can't trust bankers to govern themselves," Munger told CNBC. "A banker who is allowed to borrow money at X and loan it out at X plus Y will just go crazy and do too much of it if the civilization doesn't have rules that prevent it."

Seeing parallels between Cyprus and Iceland, Munger called it "stark, raving mad" and added that "the bankers would have been doing even more if it hadn't blown up. I do not think you can trust bankers to control themselves. They are like heroin addicts."

(Related: Buffett on Fed, IBM and His First Tweet)

Well-known investors, buy-and-hold specialist Mario Gabelli and short seller Douglas Kass, duked it out over Warren Buffett's Berkshire Hathaway on CNBC Friday from CenturyLink Center Omaha Arena, where Saturday's annual shareholders meeting will take place.

Billionaire investor Warren Buffett told CNBC that if the Federal Reserve were to increase its massive bond-buying program that would be "pretty extraordinary."

In an interview that aired on "Squawk Box" Friday, the Berkshire Hathaway chairman and CEO said, "Basically [the Fed] is buying the debt we're creating and to go beyond that is an awfully big number."

After their latest meeting, Fed policymakers said Wednesday that interest rates will remain at historically low levels, while the central bank will not alter its $85 billion a month asset-purchasing program known as quantitative easing.

Warren Buffett has sent his first tweet on his brand-new account, @WarrenBuffett. It reads, "Warren is in the house."

Buffett sent the tweet during a live streaming video interview with Fortune to promote his editorial in the magazine on why he's "bullish" on women.

Host Pattie Sellers asked if he was ready to try Twitter. He replied, "Pretty daring, but I'll try," and then asked, "Does it bite?"

After sending the tweet, he asked, "Who says you can't teach an old dog a new trick."

Just minutes after the first tweet, Buffett's account had almost 10,000 followers and that number was growing rapidly.

(Having trouble with the video? Click here!)

Fundamentally Cramer is a big fan of Warren Buffett. "I think he's brilliant," said the Mad Money host.

"No one does security analysis better than Buffett," Cramer added. His information is so thorough Buffett is sometimes called the Oracle of Omaha.

Turning attention to Buffett's company, Berkshire Hathaway, lately shares have been on a tear. Since the beginning of the year, the stock has rallied 19%, and is currently in striking distance of new all-time highs.

Even when fundamentals are fantastic, Cramer never advocates chasing gains. Considering the advance, at what levels should buyers who are interested in establishing a new position put money to work and pull the trigger?

Warren Buffett may be on safari for major acquisitions, which he likes to call elephants, but shareholders may wonder if his Berkshire Hathaway Inc has become the biggest elephant in the room.

Berkshire has grown to look more and more like corporate America, as Buffett expands outside its core insurance business into such areas as energy, industrial products, newspapers, and in February ketchup, when he teamed up with Brazil's 3G Capital investment firm to buy H.J. Heinz Co for $23.2 billion.

It's been a tough week for Warren Buffett's big investment in IBM.

Big Blue's stock plunged 8.3 percent Friday to $190 per share after the company reported disappointing first quarter revenues.

According to its most recent portfolio filing, Buffett's Berkshire Hathaway owned 68.1 million IBM shares as of the end of December.

Assuming Berkshire's stake is still around that size, Friday's slide cut the value of those shares by $1.168 billion to $12.94 billion.

That's on paper, of course. Berkshire won't actually lose any real money until it sells the shares, and given Buffett's buy-and-hold track record that won't happen until years from now, if it happens at all.

Still, it's a big number and it represents roughly half of Berkshire's paper profits on the stock it started buying in 2011.

Warren Buffett's Berkshire Hathaway and General Electric have quietly agreed to modify their almost 5-year-old warrant deal.

Warren Buffett isn't a big fan of Wall Street money managers, but he does love one of the Street's best-known names.

Buffett's Berkshire Hathaway will probably become a top-10 shareholder of Goldman Sachs in a deal revealed today.

Back in September of 2008, at the height of the credit crisis, Berkshire essentially loaned Goldman $5 billion at an interest rate of 10 percent a year. (That money was repaid in 2011.)

As part of its vote of confidence, Berkshire also received warrants giving it the right to buy another $5 billion worth of common stock at $115 per share anytime in the following five years. That purchase would work out to over 43 million Goldman shares — roughly a 10 percent stake in the company.

With Goldman shares now around $145, the below-market purchase price would generate a paper profit for Berkshire of around $1.3 billion.