According to Techcrunch, Norwest Venture Partners announced that it led a massive $210 million Series D investment round in OpenDoor. With the new capital, the startup is looking to expand the usage of its marketplace platform for buying and selling real estate to 10 cities.

OpenDoor is unique in that it owns its own inventory of homes. While the predictive analytics the company employs to project home resale value are complicated, the experience for buyers and sellers is fairly streamlined.

If you opt to sell your property on OpenDoor, you will be given a valuation from the startup. Once you accept it, OpenDoor pays you for your home and effectively 'flips' the real estate, seeking to sell it for a profit.

To entice buyers, OpenDoor allows for self-guided property tours at any time, made possible by smart locks and security cameras. If you buy a house from OpenDoor, you also receive a 180-point inspection, warranty and 30-day money-back guarantee.

This time last year, the company raised an $80 million Series C. Across all rounds, OpenDoor has now raised a cumulative $320 million. It's very likely that OpenDoor now holds a valuation that exceeds the $1 billion unicorn threshold.

Other investors, including NEA, Khosla Ventures, GGV Capital, Access Industries, FifthWall, Lakestar, SVB Capital, Caffeinated Capital and Felicis Ventures participated in today's round. Khosla's involvement is notable because OpenDoor executive chairman Keith Rabois is a partner at the venture capital firm. According to CrunchBase, Khosla Ventures has been invested since the company's initial Series A back in 2014. Prior to this round, Khosla was the largest shareholder of OpenDoor, though it's uncertain whether this remains the case after today.

Beyond venture capital financing, Norwest disclosed that OpenDoor has 'hundreds of millions'' of dollars of debt to its name. This debt is what the company uses to actually purchase properties. In the banking world, there is generally an expectation that fintech companies and marketplaces prove out their business models before they can be issued debt.

The startup believes that a 'frictionless' marketplace reduces its overall risk. The argument follows that homeowners would be willing to sell their properties for whatever they could get in a complete meltdown and OpenDoor would get a cut no matter what -- assuming the team's data analytics group is up to the nearly impossible task of predicting the future.

To date, the company has 200 employees servicing both the Dallas Fort-Worth and Phoenix markets. These regions alone account for approximately $60 million in transaction volume per month for OpenDoor.