Totally fine to need a lot of money. Actually there are a lot of fintech/alternative lending companies where debt fundraising is a big milestone because debt/capital is core to the product. This is relatively rare though.

Is OpenDoor a startup, or a REIT ?

We're a startup that builds software to simplify real estate, and we use capital markets to power that experience. The ability to buy the home directly allows us to put the homeowner in control of their timeline. I like pg's definition of startup here http://www.paulgraham.com/growth.html

Internally, we talk about fundraises as "moments" but not milestones. Fundraising takes work and is critical to growing our business, so we recognize that effort but don't celebrate rounds as successes for the business or for our customers.

their operational side looks/walks/quacks like a startup, so i think something important gets lost in translation if you look at the balance sheets and call OpenDoor a REIT