Is Sleep Number Corp. overvalued or undervalued?

As of 25 July 2018, Sleep Number Corp. has moved from a valuation grade of very expensive to risky. The company is currently considered overvalued, especially given its negative P/E ratio and a price to book value of -0.47. Key ratios include an EV to EBITDA of 9.53 and a ROCE of 14.69%.
In comparison to its peers, La-Z-Boy, Inc. has a P/E ratio of 12.21 and an EV to EBITDA of 4.68, while Ethan Allen Interiors, Inc. shows a P/E of 22.70 and an EV to EBITDA of 14.14. These comparisons highlight Sleep Number's challenging position in the market. Additionally, the company's stock has significantly underperformed against the S&P 500, with a year-to-date return of -54.40% compared to the index's 2.44%.