Berkshire Hathaway’s portfolio added six new stocks, including the three new secret stocks. Warren Buffett was a net seller of stocks for the eleventh straight quarter.

I told MarketWatch readers on Aug. 14 that Warren Buffett was about to reveal one big mystery elephant for Berkshire Hathaway’s portfolio — one $5 billion investment in the shares of an industrial giant.

See Berkshire Hathaway Inc.'s strategy with a big new stake in UnitedHealth. Learn how it's hedging against recession and stagflation. Click for my BRK.A update.

Warren Buffett's Berkshire Hathaway increased its holdings in UnitedHealth Group stock, and also added positions in D.R. Horton, Lamar Advertising, and Nucor.

What Happened: The undisclosed investments of Berkshire Hathaway have been made public. The company has reportedly invested in steelmaker Nucor NUE +1.07% Get Free Report , homebuilders D.R. Horton DHI +1.30% Get Free Report and Lennar LEN +1.56% Get Free Report , with the total investments amounting to $1.8 billion.

Berkshire Hathaway is deploying its $344B cash pile into undervalued stocks like UnitedHealth, while trimming Apple and BAC. See why BRK.A stock is a buy.

The conglomerate sold Apple shares during the second quarter, though the iPhone maker remains Berkshire’s largest stockholding.

Warren Buffett's Berkshire Hathaway has acquired 5 million shares in UnitedHealth Group , a regulatory filing showed on Thursday, sending the health insurer's stock up 7% in extended trading.

Given Buffett's concern over the stock market, it makes sense for investors to buy the most conservative stocks in the Berkshire Hathaway portfolio.