What would you have done? Zillow let its algorithm buy 7,000 homes — and lost $881 million

In 2021, Zillow was buying and reselling homes at scale, guided by its price-estimation algorithm. When the market turned volatile, the gap between predicted and actual prices widened — yet the company kept buying at a fast pace to catch up with a competitor. In November 2021 it shut the business down: an $881 million loss for the year and roughly 2,000 jobs cut, 25% of its workforce.

The lesson applies to any sector: a forecasting model's confidence is not a guarantee, especially when the market changes regime. Before letting an automated forecast drive a binding decision, have your teams set the error thresholds beyond which the machine hands back to human review, and test the model on your most atypical period, not on an average year.

Source: Zillow Group, "Fourth-Quarter and Full-Year 2021 Financial Results," February 10, 2022; CNBC, November 2, 2021.