Is Lumentum Holdings, Inc. overvalued or undervalued?

As of 17 October 2025, the valuation grade for Lumentum Holdings, Inc. moved from very expensive to expensive. Based on the current metrics, the company appears to be overvalued. Key ratios include a Price to Book Value of 6.43, an EV to EBIT of -26.73, and an EV to Sales of 5.01. In comparison, peers such as Generac Holdings, Inc. have a more attractive P/E of 30.37 and EV to EBITDA of 18.40, while Acuity Brands, Inc. shows a fair P/E of 38.19 and an EV to EBITDA of 24.96.
Despite Lumentum's strong stock performance, with a year-to-date return of 96.27% compared to the S&P 500's 13.30%, the high valuation ratios suggest that the stock is not justified at its current price levels.