Is Illumina, Inc. overvalued or undervalued?

As of 31 October 2025, the valuation grade for Illumina, Inc. has moved from fair to expensive, indicating that the company is currently overvalued. Key valuation ratios include a P/E ratio of 26, a Price to Book Value of 6.89, and an EV to EBITDA of 9.89, all of which suggest that the stock is trading at a premium compared to its peers. For instance, Biogen, Inc. has a P/E ratio of 13.57, highlighting a significant disparity in valuation between the two companies.
Furthermore, Illumina's PEG ratio stands at an exceptionally low 0.07, which typically indicates a potential undervaluation based on growth expectations; however, the overall high valuation metrics suggest otherwise. In terms of recent performance, Illumina has underperformed against the S&P 500, with a year-to-date return of -12.55% compared to the index's 16.30%. This trend of underperformance over multiple periods reinforces the conclusion that Illumina, Inc. is overvalued in its current market context.