Short reports, especially from notable entities like Spruce Point, can significantly impact investor sentiment and stock prices. Given the report's negative outlook, it's likely that Zillow's Class C shares will experience a decrease in value in the short term as investors react to the potential risks highlighted.

The release of a short report by Spruce Point is expected to negatively impact Zillow Group's Class A shares as well, due to the shared concerns about the company's future performance and valuation. This could lead to a decrease in stock price as investors may sell off their shares in response to the perceived increased risk.