Airbnb is now worth $30 billion after raising a fresh $550 million

Airbnb has raised $550 million toward an expected $850 million round, a sizable chunk of cash as the company continues to grow globally.

A source close to the company confirmed earlier reports from the Wall Street Journal and Fortune.

The funding round is reportedly from Google parent company Alphabet. The Airbnb source would not comment on investors behind the round.

The $550 million goes toward $850 million the company filed to raise in July. The round values Airbnb at $30 billion, making it one of the biggest startups in recent years to remain private.

Airbnb's fundraising round hasn't closed and the company will have additional filings, the source said.

Google Capital and growth-equity firm Technology Crossover Ventures led the round, according to the Journal.

As part of the deal, employees who have been with Airbnb for longer than four years reportedly were able to sell common shares to investors, totaling $200 million. This has become an important way for companies to reward their employees without having to enter the public market.

Google Capital is a growth-equity arm of the company that has invested in companies including SurveyMonkey, GlassDoor, Care.com and Duolingo.

Technology Crossover Ventures has invested in Facebook, Netflix, Vice, LinkedIn, Spotify, SeatGeek, Dollar Shave Club and eHarmony.

Airbnb's previous lead investors include Andreessen Horowitz, Founders Fund, General Atlantic and Hillhouse Capital Group.

The funding round arrives as Airbnb prepares to — and puts off — going public.

A year ago, Airbnb was valued at $25.6 billion compared to today's $30 billion valuation.