Zillow Group Inc. /zigman2/quotes/204413973/composite Z +11.32% is pausing the purchase of U.S. homes as it works through a backlog of properties, Bloomberg News reported Sunday. The real-estate platform acquired more than 3,800 homes in the second quarter, after expanding into the home-flipping business in 2018 through its Zillow Offers unit. That company invites homeowners to request an offer on their house and uses its algorithms to come up with a price. If an owner accepts, it purchases the property, makes some repairs and puts it back on the market. "We are beyond operational capacity in our Zillow Offers business and are not taking on additional contracts to purchase homes at this time," a spokesperson for Zillow told Bloomberg in an email. "We continue to process the purchase of homes from sellers who are already under contract, as quickly as possible." The iBuying process, while powered by algorithms and pools of capital, also requires humans, including inspectors, contractors and decorators. But finding those workers has become challenging during the pandemic, which has see labor shortages across the economy. Zillow shares were down 6% premarket and have fallen 26% in the year to date, while the S&P 500 /zigman2/quotes/210599714/realtime SPX -0.84% has gained 19%.