News · Alnylam Pharmaceuticals, Inc. (ALNY) · Healthcare

Alnylam falls 25.1% after third-quarter results spark heavy sell-off

Session of October 29, 2026 · Published October 30, 2026 · 3 min read

What happened

Alnylam (ALNY) fell 25.1% on October 29, 2026, because its third-quarter results, while far above expectations, provoked heavy selling and a spike in volatility. The company reported quarterly earnings per share of $16.26 against $1.66 expected, 879.5% above estimates, and global net product revenue of approximately $1.3 billion, up 52% year-over-year, according to Seeking Alpha and Zacks Investment Research.

Closing price over the last 30 trading sessions. On October 29, 2026, ALNY closed at $174.00, down 25.1% on the day and 27.4% lower than 30 sessions earlier.

How big was the move

The stock closed at $174.00 after a session that amounted to 5.4 times a typical daily move for this stock, and trading volume ran 8.4 times its 20-day average. Over the last five sessions the stock fell 23.4% while the S&P 500 rose 0.7% in that span and the healthcare sector median rose 0.5%, leaving the move 25.6 percentage points worse than the sector median. The S&P 500 fell 0.3% on the day, and the session was company-specific because earnings were released at this session.

Each bar is one day's price change; the outlined bar is October 29, 2026. A typical daily move over the past year was 3.0%, so the latest move equals 8.3 times that. Moves outside the dashed lines (about 6.1%) are unusual.

The technical picture

The stock opened 20.1% below the previous close and finished 22.5% below its 20-day moving average, and 26.8% below its 50-day moving average. The 50-day average is below the 200-day average, a sign of a weak longer-term trend, and the stock is 64.0% below its 52-week high. Momentum measures reflected the sell-off: the 14-day Relative Strength Index is 24, below 30 and often called oversold, while 60-day volatility is 73% annualized, higher than 89% of its own readings over five years. Over one month the stock fell 29.5%, over three months it fell 15.3% and over one year it fell 63.4%, leaving it 75.5 percentage points behind the S&P 500 for the one-year period.

Closing price over the past year. ALNY ends the period 63.9% below its 52-week high, below its 50-day average ($237.78) and below its 200-day average ($286.49).

Fundamentals and valuation

For the four quarters through September 30, 2026, Alnylam reported revenue of $5.01 billion, up 56.2% from a year earlier, and diluted earnings per share of $19.80, a rise of 8,150.0% from a year earlier. Gross margin declined to 77.3% from 84.0% a year earlier, while operating margin improved to 19.5% from 8.2%. Free-cash-flow margin stood at 10.0% and the balance sheet showed net cash of $492.3 million. The company’s market value was $29.98 billion.

Quarterly revenue by period end. The latest quarter brought $1.5B, 16.7% more than the same quarter a year earlier.

On valuation, the stock trades at 8.8 times trailing earnings and 26.8 times forward earnings, with a free-cash-flow yield of 1.7%. PromtFinance scores place Alnylam highly for Growth at 88 and Value at 80, while Momentum is weak at 6, and Stability is neutral at 60. Those mixed signals underscore a company showing rapid fundamental gains but suffering recent market antipathy.

Earnings and analyst expectations

Alnylam’s October 29, 2026, report delivered earnings per share of $16.26 versus $1.66 expected, 879.5% above estimates. That marked one consecutive quarter beating estimates and an average surprise of 100.0% over the last four reports. The company’s typical two-day reaction after recent reports was a fall of 6.2%, far smaller than the plunge this session produced.

Diluted earnings per share by quarter. The latest quarter shows $15.72, against $1.84 in the same quarter a year earlier.

Analysts place a consensus price target of $347.23, 99.6% above the closing price, based on 52 analysts, and 75% of ratings are Buy or Strong Buy. The next scheduled report is February 18, 2027.

Two items in recent news are likely to have bearing on investor sentiment. First, Alnylam reported third-quarter net product revenue of approximately $1.3 billion, up 52% year-over-year and 10% sequentially, driven by growth in its transthyretin (TTR) franchise, according to Seeking Alpha and Zacks Investment Research. Second, a law firm announced an investigation into possible securities fraud related to a July 30, 2026, disclosure tied to a 28.31% share price decline, according to GlobeNewsWire. That inquiry adds a legal overhang to an otherwise strong operating report.

What to watch

February 18, 2027: next scheduled earnings report.
Consensus price target of $347.23, 99.6% above the October 29 close.
Share count increased by 0.5% over one year and net cash of $492.3 million.
Recent news: third-quarter net product revenue approximately $1.3 billion, up 52% year-over-year, reported by Seeking Alpha and Zacks Investment Research.
A law firm announced an investigation into possible securities fraud linked to a July 30, 2026, disclosure, reported by GlobeNewsWire.

Full ALNY analysis: scores, chart and financials →