Warren Buffett's Berkshire Hathaway was an aggressive buyer of stocks in last year's fourth quarter, nearly quadrupling its stake in Apple and increasing its stake sevenfold in the four biggest U.S. airlines.
In a regulatory filing, Berkshire reported owning 57.4 million shares of Apple as of Dec. 31, which would now be worth $7.74 billion, up from just from 15.2 million shares in the iPhone maker three months earlier.
Berkshire's initial investment in Apple got attention last year, given Buffett's usual aversion to technology companies, apart from IBM, which he considers outside his zone of competence.
The new, larger stake makes Berkshire one of Apple's 10 biggest investors.
Shares of Apple closed on Tuesday up $1.73 at $135.02, also a record closing high.
Assuming Berkshire has not sold its stake, Apple's 16.6 percent gain this year would leave it with a $1.1 billion paper profit in 2017 alone.
It had been widely believed that Berkshire's initial investment came from Combs or Weschler.
But their decisions have sometimes influenced Buffett, as when Berkshire last year paid $32.1 billion for aircraft parts maker Precision Castparts Corp, once a Combs investment.
Combs and Weschler are the leading candidates to eventually succeed Buffett as Berkshire's chief investment officer.
Shares of American, Delta, Southwest and United, as well as Apple, Monsanto and Sirius, rose in after-hours trading.
To make room for new investments, Berkshire appeared to have shed a $1.8 billion stake in agricultural equipment maker Deere & Co and nearly all of what remained from a more than decade-old stake in retailer Wal-Mart Stores.