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.

Rail company BNSF Railway expects to be moving a million barrels of oil a day in the not too distant future, and it would like to move it with natural gas powered locomotives.

The domestic oil and gas drilling boom has made oil more plentiful and gas abundant and cheap. The oil is locked in the mid-Continent, awaiting new pipelines, but it already is moving on trains.

Natural gas is now cheap enough to be considered as a fuel for locomotives and other vehicles.

During his live appearance on CNBC's "Squawk Box" today, Berkshire Hathaway Chairman Warren Buffett had some valuable advice for individual investors on how to make sure they are getting a "fair shake" on Wall Street.

Warren Buffett has some advice for Apple CEO Tim Cook on how to respond to activist investor David Einhorn's very public calls for some of the company's vast cash holdings to be returned to shareholders.

Ignore him.

Warren Buffett still sees "good value" in stocks, even as the Dow Jones Industrial Average approaches an all-time high.

On CNBC's Squawk Box, Buffett said Berkshire Hathaway is still buying stocks, even though prices have increased.

Warren Buffett called 2012 "subpar" in his annual letter to shareholders as Berkshire Hathaway's per-share book value rose 14.4 percent, less than the S&P 500's 16-percent increase.

It's the ninth time in 48 years this has happened. Buffett notes that the S&P 500 has outpaced Berkshire over the past four years, and if the market continues to gain this year the benchmark stock index could have its first five-year win ever.

"When the partnership I ran took control of Berkshire in 1965, I could never have dreamed that a year in which we had a gain of $24.1 billion would be subpar. ... But subpar it was."

Buffett has found his bear.

In his letter to shareholders published on Friday, Warren E. Buffett said that "to spice things up" he wanted to find a money manger with an unfavorable view of Berkshire Hathaway to participate in the company's annual meeting.

"The only requirement is that you be an investment professional and negative on Berkshire," he wrote.

On Monday, Mr. Buffett said Doug Kass, a hedge fund manager, would be added to the panel of analysts who question Mr. Buffett and Berkshire's vice chairman, Charles T. Munger, on stage during Berkshire's annual gathering in Omaha on May 4.

There is a cottage industry dedicated to answering the question: "what would Warren do?"

Warren Buffett's investment principles, laid out in his annual letter to shareholders of Berkshire Hathaway, have inspired guides, imitators and even children's books. Thousands travel to Omaha, Nebraska each year to hear him elaborate at the conglomerate's annual meeting.

When the next dispatch arrives late on Friday, readers will hope to find an explanation of the thinking behind his latest $12 billion-$13 billion investment, the purchase of ketchup maker Heinz with Brazilian buyout group 3G Capital.

Yet the letter is likely to answer in only the most general terms the query: "what will Warren do next?"

Warren Buffett will be live with Becky Quick for all three hours of CNBC's Squawk Box this coming Monday morning and we want to know what you would ask him.

Send us your questions by email to AskWarren@cnbc.com or by Twitter with the hashtag #askwarren.

We'll use some of them when the Berkshire Hathaway chairman makes his sixth annual "Ask Warren" appearance starting at 6 am ET on Monday, March 4.

Becky will also be asking him about his annual letter to Berkshire shareholders, due to be released on Friday after the U.S. stock markets close, along with the company's Q4 and 2012 financial results.

During last year's "Ask Warren," Buffett generated headlines when he said he'd buy up "a couple hundred thousand" single family homes if it were practical to do so.