Airbnb has closed on a more than $1 billion round of funding, a source close to the company told CNBC. The round was confirmed in an SEC filing that dropped on Thursday. It is now worth approximately $31 billion.

The company raised roughly an additional $450 million as part of its Series F round, making the round nearly twice as much as it stood last fall. The total amount raised was $1,003,312,065, according to the filing.

The company also turned profitable in the second quarter of 2016, a person close to the company confirmed with CNBC. The home-sharing giant further expects to be profitable this year, the source said, and has no plans to go public soon. (That's EBITDA profitability, according to the Wall Street Journal, meaning that expenses like taxes are not included.)

Since its start in 2008, Airbnb has raised more than $3 billion.

Airbnb was last reported to be raising cash at a $30 billion valuation, making it the second-most valuable start-up in the U.S., trailing only Uber. This latest round of funding ups the valuation to approximately $31 billion.

Although details weren't provided on how Airbnb plans to use funds, it likely will aim to grow operations globally. With a stronger balance sheet, the San Francisco-based start-up is enjoying much more "operational flexibility" now.