Opendoor cut prices and gave incentives in the third quarter, losing cash on much of its inventory.
Opendoor has been offering buyers $15,000 credits and their brokers $3,500 bonuses.
A decelerating housing market poses a challenge for iBuying companies like Opendoor, which use home-pricing algorithms to purchase homes.
In the third quarter, Opendoor sold between 8,100 and 8,550 homes, according to an estimate by Datadoor, a startup that catalogs Opendoor's acquisition and sales activity across the country.
The high end of Datadoor's estimate, 8,550 home sales, would be an 18% decrease in the number of sales Opendoor reported for the second quarter and 32% below the first quarter.