Illumina Stock Lags Old Highs Despite Business Growth and Margin Gains

Illumina (ILMN) shares ended trading at $214.91 on November 10, 2026, according to Trefis. That close leaves the stock 57.9% beneath its split-adjusted record high of $510.06 reached on August 16, 2021. To reach that peak again, the stock would need to rise 137.3%, an advance that would require a 33.4% annual return if achieved across three years. Trefis noted that rolling three-year stretches over the past ten years delivered a gain of 137.3% or more in only 1.7% of instances.

Despite the prolonged slump from its 2021 price, Illumina generated more revenue and wider margins during the twelve months leading to September 2026 than in the year prior to its former high, Trefis reported. Revenue was up 14.4%, while operating margin reached 21.4% compared to 17.0% previously. On an October 29 call, corporate leadership said about 360 NovaSeq X instruments were placed over the preceding four quarters and noted that tariff refunds helped lift the latest quarter's operating margin to 27.0%. Illumina shares trade at 7.2 times sales, down from 16.9 times at the end of June 2021.

Even with lower sales multiples than in 2021, valuation metrics have sparked caution. According to GuruFocus, Illumina shares closed at $220.78 on November 09, 2026, after rising 3.6%. GuruFocus calculated an intrinsic GF Value of $136.35, viewing the stock as 61.9% overvalued. The platform assigned Illumina a GF Score of 68/100, citing an 8/10 moat rating alongside a 1/10 valuation ranking, and observed that the stock's price-to-earnings ratio of 37.9x sits above its five-year median of 33.4x.

Trading had previously been volatile, with shares sliding 8.2% to $208.00 on November 05, 2026, GuruFocus reported. The platform noted that over the trailing 12 months, company insiders sold $659.4M worth of stock with zero purchases. In institutional holdings, GuruFocus tracked 13 gurus, with 5 increasing holdings and 8 trimming stakes.

Earlier in the quarter, Mott Thematic Growth Strategy reported in its Q3 2026 investor letter that it trimmed its Illumina position to take profits following strong performance and a favorable FDA advisory panel vote for Grail. Illumina closed at approximately $226.58 on November 2, 2026, Mott Capital stated. Previously, Calamos Global Equity Fund noted in its Q3 letter that Illumina surpassed quarterly revenue and earnings estimates, as the stock closed at $267.93 on October 20, 2026.