Meal delivery startup DoorDash Inc. has raised $250 million in a new round of funding for its expansion, putting its valuation at $4 billion, the company announced Thursday.

The San-Francisco-based business received its new investment from Coatue Management, DST Global, and several other investors. This comes after the company in March raised $535 million from SoftBank Group Corp, Sequoia Capital, and Singapore’s GIC—in a Series D financing round, increasing its valuation to $1.4 billion at that time.

DoorDash, meanwhile, has seen an uptick in business, as its delivery volume has increased 250 percent in June compared to the same time last year. In January, DoorDash reported a 150 percent year-over-year growth in its deliveries. Following March funding, the company shared plans to grow from serving 600 cities to 1,600. It’s now serving 1,000, according to Bloomberg.

"As we grow, we will stay true to our values and our mission of connecting people with possibility — and, trust us, we’re just getting started," the company said in a blog post earlier this year.

News of DoorDash’s new funding comes at a time where companies like Postmates, Uber Eats, and several other startups are competing for dominance in the online food delivery space. According to Bloomberg, it is estimated that online delivery grossed $19.7 billion in U.S. restaurant sales in 2017.

Meanwhile, DoorDash has expanded its reach by partnering with Walmart for a national grocery delivery service, which exists at almost 300 stores in 20 states. The company's CEO, Tony Xu, said he believes the startup is successful because of the restaurants that are in its portfolio and its business model. 

"We never raised money until we had a proven model," he told Fortune in an interview Thursday. "We’re seeing success in our milestones earlier and at greater magnitude than ever before. We want that to continue."

DoorDash allows restaurants to provide delivery services to its customers. It was founded in 2013 by Stanford students Andy Fang, Stanley Tang, Evan Moore and Xu. It currently has partnerships with big restaurant chains such as Wendy’s, Jack In The Box, Buffalo Wild Wings, Chick-Fil-A, Wingstop, IHOP, and Five Guys.