WeWork is planning to sell $500 million (£358 million) in high-yield notes, per reports from the Financial Times and Bloomberg this week.

And bond documents reviewed by the two publications reveal some startling numbers -- here's a summary:

WeWork owes $18 billion in rent. The company has more than 14 million square feet of office space, with suitably massive lease obligations, although WeWork has the option of closing locations if it can't pay those bills.

The company has more than 14 million square feet of office space, with suitably massive lease obligations, although WeWork has the option of closing locations if it can't pay those bills. WeWork is burning cash. Revenue from memberships more than doubled last year, to $822 million, but expenses also more than doubled, to $1.81 billion. Net losses came to $934 million, according to Bloomberg.

Revenue from memberships more than doubled last year, to $822 million, but expenses also more than doubled, to $1.81 billion. Net losses came to $934 million, according to Bloomberg. It isn't really about tech startups. About 20 percent of WeWork's occupants are in financial, legal, and business services, while 15 percent work in software.

About 20 percent of WeWork's occupants are in financial, legal, and business services, while 15 percent work in software. A focus on bigger companies means higher occupancy rates. Filling desks--and keeping them filled--is an important metric for WeWork, which says it has done so with 81 percent of them, higher than its minimum requirement of 60 percent occupancy to cover costs.

Filling desks--and keeping them filled--is an important metric for WeWork, which says it has done so with 81 percent of them, higher than its minimum requirement of 60 percent occupancy to cover costs. Like other tech CEOs, Adam Neumann controls the company. He has more than 65 percent of the voting power.

WeWork has expanded rapidly, helped by the $4.4 billion it raised last year from its main backer, SoftBank. According to its bond documents, the company had 220,000 members as of March, and 251,000 desks across 234 locations.

Skeptics worry that WeWork is overly exposed to market shifts that could affect its occupants and their willingness to pay membership fees. But the optimistic view is that WeWork's leases will eventually generate more cash than its costs as occupancy rates rise and the company gets its upfront spend on the "fit-out" for new properties out of the way.

This post originally appeared on Business Insider.