VeriSign is ranked 5th in the S&P 500 for the highest profit margin, at about 56%, tied with Nvidia, according to third-quarter financial data.

Geico, and pension plans of other Berkshire Hathaway units bought nearly $30 million of shares of domain-name registry firm VeriSign.

Berkshire Hathaway (NYSE: BRK.A)(NYSE: BRK.B) has been one of the most successful stock investments of all time. Plus, many people reading this aren't old even enough to have bought Berkshire stock in the 1960s.

Warren Buffett’s Berkshire Hathaway Inc. has been busy over the past week buying stock in an internet domain-name registry company, to extend its stature as the company’s largest shareholder.

Warren Buffett has invested more than $74 million in a Reston company best known for controlling internet domains for organizations across the globe.

For decades, Berkshire Hathaway's stock was only available through over-the-counter markets. But on Nov. 29, 1988, it listed what are now known as its Class A shares on the New York Stock Exchange. In his shareholder letter that year, Buffett said his main motivation was minimizing investors' transaction costs.

Shares of Berkshire Hathaway Inc. Cl B slipped 0.56% to $456.51 Friday, on what proved to be an all-around dismal trading session for the stock market, with the S&P 500 Index falling 1.11% to 5,970.84 and Dow Jones Industrial Average falling 0.