Warren Buffett’s Berkshire Hathaway Inc. (BRK-A) bought an eye-popping 43.2 million shares of Southwest Airlines in the fourth quarter. Berkshire’s new position in the low-cost carrier is valued at $2.2 billion, according to a federal regulatory filing published Tuesday, February 14.

Southwest Airlines Co. (LUV - Free Report) shares rose 0.89% in after-hours trading Tuesday, to $55.80. And the U.S. airline currently holds a Zacks Rank #2 (BUY). Southwest is the No. 4 airline in the U.S. in terms of traffic, but it holds the top spot for domestic flights.

The massive bet on Southwest signals a shift in Buffet’s decades-long stance on airlines being money-losers. Berkshire’s fourth quarter faith in Southwest comes after the Omaha, Nebraska-based company invested heavily in American Airlines Group, Inc. (AAL - Free Report) , Delta Air Lines, Inc. (DAL - Free Report) and United Continental Holdings, Inc. (UAL - Free Report) in the third quarter. It then added to all three of those positions in the fourth quarter.

In the first nine months of 2016, Berkshire bought a total of $5.2 billion worth of stocks, according to a regulatory filing.

Berkshire invested a total of about $9.3 billion in airlines at the end of 2016. Berkshire’s investment heavy fourth quarter seemingly signals the company’s confidence in the market and business climate, post election.

“We’ve, net, bought $12 billion of common stocks since the election,” Buffet said in a recent interview with Charlie Rose.

Top executives from major U.S. airlines, including Southwest CEO Gary Kelly, met with President Donald Trump last week. Despite Trump’s recent controversial travel ban from seven Muslim-majority nations, which saw airline stocks fall temporarily, it seems the airline industry could start to see an uptick.