Even if Zillow had an algorithm that was 100% accurate at predicting current house prices, the housing market is just incompatible with market making. A market maker isn’t exposed to changes in the price, they clip the ticket on providing liquidity regardless of price direction. Zillow may have been able to successfully speculate on house prices with an accurate model, but they would not be a market maker.
Houses trade slowly, so would sit on Zillows books for a long time (days/months). Market makers on the stock market can have assets sit on the books for under a second. Houses are not fungible, which extenuates the slow trade problem.
Houses trade slowly, so would sit on Zillows books for a long time (days/months). Market makers on the stock market can have assets sit on the books for under a second. Houses are not fungible, which extenuates the slow trade problem.