Psst ... Billionaire investor Warren Buffett's Berkshire Hathaway could be quietly making a secret purchase.
The most tantalising element of a disclosure, filed with the U.S. Securities and Exchange Commission, was what had been left out.
"Confidential information has been omitted from the public Form 13F report and filed separately with the U.S. Securities and Exchange Commission," it said.
This means Berkshire chose to keep some of the details about its holdings confidential. Buffett has previously used this tactic to build up stakes in new firms without other investors piggybacking. He requested confidentiality from the SEC when amassing stakes in IBM and Exxon Mobil in 2011 and 2013 respectively.
The filing, detailing the firm's $107.2bn US stock portfolio on June 30, also revealed some minor changes. It showed Berkshire boosted its stake in telecoms company Charter and Communications and could've shed its stakes in a couple of oil field equipment providers.