Is Illumina, Inc. overvalued or undervalued?

As of 31 October 2025, Illumina, Inc. has moved from fair to expensive, indicating a shift in its valuation grade. The company appears overvalued, with a P/E ratio of 26, significantly higher than its peer BioMarin Pharmaceutical, Inc. at 15.17 and Elanco Animal Health, Inc. at 19.25. Additionally, the EV to EBITDA ratio stands at 9.89, which is also above the industry average, suggesting that the stock may not be justified at its current price level.
In terms of performance, Illumina's returns have lagged behind the S&P 500, with a year-to-date return of -10.21% compared to the index's 16.30%, and a 5-year return of -58.38% versus 109.18% for the S&P 500. These figures reinforce the notion that Illumina is overvalued relative to its peers and the broader market.