Food-delivery service DoorDash announced on Thursday that it has filed a confidential S-1 with the Securities and Exchange Commission, the first step for the company to go public. It's just the latest development for the company after a very successful 2019, in which it signed exclusive delivery contracts with large restaurant chains like Outback Steakhouse of Bloomin' Brands (BLMN -1.80%), and overtook competitor Grubhub (GRUB) as the largest third-party delivery service in the country, according to a report by CNBC.

Previously, DoorDash tapped the private equity markets for funding. In May 2019, it announced $600 million in private funds, bringing the company's valuation to nearly $13 billion. The market capitalization of Grubhub is $3.1 billion for comparison.

A man delivers food to a woman.

Image source: Getty Images.

The food-delivery space

For restaurant stocks, increasing sales volume is challenging. But food delivery via third-party carriers like DoorDash has opened up a new avenue to grow comparable-restaurant sales. Bloomin' Brands in its fourth-quarter earnings call said that, thanks to its new partnership with DoorDash, off-premise orders grew 20% year over year, and now account for 15% of all sales.

DoorDash's rivals include Grubhub and Uber Technologies (UBER -0.57%) with its Uber Eats. To overcome competitive challenges, third-party delivery services are turning to loyalty programs. Grubhub recently announced a subscription service that provides perks for members. Uber also has a loyalty program for its services. DoorDash's subscription membership is called DashPass. 

Investors hungry for DoorDash's IPO likely have much longer to wait. Competitor Postmates filed a confidential S-1 over a year ago, and has yet to go public. Whenever DoorDash does decide to finally go public, potential investors aren't likely to have much time to review its financials. Per the SEC's confidential-filing rules, DoorDash only has to release filings 15 days before the IPO.