Illumina Inc. stock gains on S&P 500 inclusion and strong 12-month rally

Published on 09/19/2026 at 16:53 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS

Illumina Inc. stock has climbed 143.07% over the past 12 months, closing at USD 239.55 on September 18, 2026, according to Morningstar. The shares now trade near USD 239.62 as Illumina joins the S&P 500 Index effective September 21, 2026.

Schwarzweiß-Reportagefoto einer Wissenschaftlerin beim Pipettieren im Genomiklabor — Illumina Inc. zeigt US4523271090 in dokumentarischer Schwarzweiß-Reportage einer Wissenschaftlerin beim Pipettieren im Labor, Illustration mit AI erstellt.

Illumina Inc. stock (ISIN US4523271090) closed at USD 239.55 on the Nasdaq on September 18, 2026, capping a 143.07% gain over the past 12 months, according to Morningstar.

Index inclusion lifts Illumina profile

Illumina Inc. stock is set to enter the S&P 500 Index, with the change taking effect before the market opens on September 21, 2026, according to Futunn.

The addition to the S&P 500 means Illumina will be included in a widely tracked benchmark, which can increase demand from index funds and other passive strategies that replicate or reference the index, as highlighted by TradingView.

Price performance and technical context

Per data summarized by Morningstar, Illumina Inc. stock gained 16.02% in the latest trading week and 54.11% over the last three months, underscoring the strength of its recent rally.

The same overview notes that the shares finished that week at USD 239.55, trading at a 49% premium to Morningstar's fair value estimate of USD 165 per share, which suggests the market is currently assigning a significant valuation premium to the company relative to that fundamental assessment.

A separate technical view from StockTradersDaily lists a current price signal around USD 239.62, with near-term support at USD 239.42 and resistance at USD 248.60, indicating that the stock is trading near the lower end of its identified breakout trigger zone.

Analyst targets and guidance frame expectations

According to an analyst overview on MarketBeat dated September 19, 2026, UBS Group raised its rating on Illumina Inc. stock from neutral to buy and lifted its price target from USD 135.00 to USD 260.00 in a research note on September 9, 2026.

The same MarketBeat overview reports that Argus boosted its price target on Illumina Inc. stock from USD 180.00 to USD 235.00 and assigned a buy rating in a report dated September 3, 2026, adding another bullish call to the recent analyst flow.

Across the broader analyst community, MarketBeat indicates that Illumina currently has a consensus rating of Hold, with an average target price of USD 199.12, which sits below both UBS's upgraded target of USD 260.00 and Argus's revised USD 235.00 level and below the latest share price near USD 239.62.

In addition to external analyst views, Illumina has set fiscal year 2026 earnings guidance at USD 5.30 to USD 5.40 per share, as summarized by MarketBeat, framing the company's profitability expectations for the current fiscal year.

Relative performance and valuation risk

An AI-powered comparison from AltIndex updated on September 19, 2026, shows Illumina Inc. stock priced at USD 239.62 with a market capitalization of USD 37.02 billion and a 12-month change of plus 133.8%.

In the same comparison, peer company Revolution Medicines is reported to have gained 384.2% in market cap over the past 12 months, highlighting that while Illumina's rally has been strong, other biotechnology names have seen even steeper moves, which can influence sector positioning and investor rotation.

AltIndex assigns Illumina an AI Score of 37 versus 78 for Revolution Medicines, which suggests that, based on its alternative data and scoring methodology, Illumina may rank lower on certain sentiment or data-driven metrics despite its substantial share price appreciation.

Morningstar's valuation framework, which finds Illumina trading at a 49% premium to a fair value estimate of USD 165 per share, underlines that valuation risk is an important counter-factor for investors to weigh alongside the positive price momentum and upcoming S&P 500 inclusion reported by Morningstar.

Stock level and investor takeaway

Illumina Inc. stock was most recently quoted around USD 239.62 on the Nasdaq, close to the USD 239.55 end-of-week level reported for September 18, 2026, and reflecting a 133.8% price increase over the past 12 months as of that date, according to AltIndex.