According to ChainCatcher, Buffett's Berkshire Hathaway purchased an additional 143,424 shares of VeriSign for $28.55 million in the three trading days ending December 24.
With the previously purchased shares, Berkshire now holds 13.7% of VeriSign's outstanding shares, worth nearly $2.7 billion. One of the reasons Buffett is interested in VeriSign is that its profit margin index ranks high among S&P 500 companies.
VeriSign has been granted a patent by the U.S. Patent and Trademark Office for the application of blockchain technology to domain names, and has control over ".com" and ".net" domain names. The patent supports the use of traditional DNS domain names in a blockchain environment.