If a company has negative enterprise value, what does that mean?

This means that the company must have more cash than the equity value, debt, and preferred equity combined together. Cash is subtracted from the enterprise value, so the larger cash is, the lower the enterprise value. The company also likely has a suppressed equity value due to negative investor sentiment. Investors are expecting the company to perform so poorly such that the company is not even worth the cash it holds. It’s possible that the company is expected to pay a large lawsuit, absorb a large expense, or simply burn cash at an unsustainable rate.