5 Green Days In A Row: Illumina Stock Is Up 22%
A five-day rally in Illumina stock has drawn attention, but the move puts its valuation further ahead of its underlying growth.
Illumina (ILMN) stock has now moved higher for 5 consecutive trading days, gaining a cumulative 21.8% over the period. That run has added about $6.6 billion to the company’s market value, which now stands at about $37 billion.
The stock trades at about $245.18 a share as of 9/17/2026.
How The Streak Stacks Up Against The S&P 500
Here is how ILMN stock stacks up against the S&P 500 over the streak and the periods around it:
| Return Period | ILMN | S&P 500 |
|---|---|---|
| 1D | 7.1% | 1.1% |
| 5D (Current Streak) | 21.8% | 0.6% |
| 1M (21D) | 30.2% | -0.7% |
| 3M (63D) | 54.1% | 2.9% |
| YTD 2026 | 86.9% | 11.6% |
| 2025 | -1.8% | 16.4% |
| 2024 | -1.2% | 23.3% |
| 2023 | -31.1% | 24.2% |
Is the price getting ahead of the business?
The move is largely the stock’s own, not a reflection of the broader market. During the five-day streak, the S&P 500 returned just +0.6%.
From a valuation standpoint, Illumina trades at a price-to-earnings multiple of 44.9. That is above the median of 25.9 across the broader Health Care sector.
Revenue over the last twelve months grew 4.9%, trailing the peer median of 8.1%. The company’s operating margin, however, is 19.9%, which is ahead of the 17.6% median.
A streak is information, not an instruction.
Sustained momentum of this magnitude signals heightened market focus, but it is not, on its own, a directive to buy or sell.
The disciplined next step is to check the business against the price. The data here presents a clear tension for investors to consider: a powerful rally against a high valuation and revenue growth that lags its peers.
If you are hunting for strength that has more behind it than a hot tape, our Guidance Momentum screen surfaces the names where management raised its own outlook, which is the kind of momentum that tends to persist.
Those drawn to the strength but not the single-name risk have another route: our ETF Scorecard shows how the health care funds stack up. Any one of those funds is still a concentrated bet on that one theme, though, which is exactly the gap the portfolio below closes.
Streaks End. Discipline Compounds
A run like this is genuinely useful information: something about this business has the market’s full attention. But streaks are where discipline gets tested, because the urge to chase strength is strongest right before it pauses.
The Trefis High Quality (HQ) Portfolio channels that urge into a system: roughly 30 businesses selected for consistent cash generation, strong margins, and resilient balance sheets, sized and rebalanced with rules rather than excitement. It has a track record of outpacing a benchmark that combines the three major indices – the S&P 500, S&P Mid-cap, and Russell 2000. Enjoy the streak; own the process.