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# Alnylam Stock Plunges 16%, Wiping Out $5.1 Billion, As Management Says Amvuttra Demand Lags
- URL: https://www.bullished.co/alnylam-stock-plunges-16-wiping-out-5-1-billion-as-management-says-amvuttra-demand-lags-d0f92b1c/
- Published: 2026-10-29T14:36:32.000Z
- Updated: 2026-10-29T14:36:32.000Z
- Description: The RNA drugmaker will hold 2027 guidance until mid-February, and management says it is "not yet satisfied" with Amvuttra growth.
- Author: Matteo Parrino
- Tags: Markets, ALNY, Industry: Healthcare

[Alnylam Pharmaceuticals](https://www.bullished.co/tag/alny/), which develops medicines based on RNA interference, plunged 16.26% to $194.61 in Thursday trading as of 10:35 a.m. ET, erasing $5.1 billion in market value, after management said demand for its heart drug Amvuttra has not yet responded to a bigger sales force. The drop came on the day it reported [third-quarter revenue of $1.46 billion](https://seekingalpha.com/news/4660169-alnylam-pharmaceuticals-non-gaap-eps-of-16%5F26-beats-by-14%5F01-revenue-of-1%5F46b-beats-by-30m?ref=bullished.co) and net income of $2.2 billion.

## A tax gain flatters the quarter

Alnylam attributed the $2.2 billion in net income to a tax gain, while core operating income slipped, according to its [quarterly results](https://www.sec.gov/Archives/edgar/data/1178670/000117867026000076/alny-20260930.htm?ref=bullished.co).

On the earnings call, management said it is "not yet satisfied" with demand growth for Amvuttra and expects no acceleration in the fourth quarter, despite the larger sales force.

The stock was on pace for its biggest one-day drop since July 30, when it fell 28.3%.

## Guidance pushed to mid-February

Alnylam also said it will give 2027 product revenue guidance in mid-February rather than at the JPMorgan conference. It cited a pending Medicare drug-discount rule and a UnitedHealth policy change.

Amvuttra treats transthyretin amyloidosis. The annual report also lists Onpattro for that disease, plus Oxlumo for primary hyperoxaluria type 1 and Givlaari for acute hepatic porphyria, and says the company runs more than 20 clinical programs.

## Down 42% before the drop

Alnylam shares were down about 42% year to date at Wednesday's close, while the S&P 500 was up about 13% over the same span. The stock already sat 52% below its highest close of the past year, set on October 29, 2025.

After Thursday's slide the company's market value was $26.04 billion.

Alnylam plans to give its 2027 product revenue guidance in mid-February.

### Sources

- [Alnylam: Q3 Earnings Snapshot](https://finance.yahoo.com/markets/stocks/articles/alnylam-q3-earnings-snapshot-121432555.html?ref=bullished.co) — Associated Press
- [Alnylam Pharmaceuticals (ALNY) Stock Looks Fully Priced Following Its 52% Fall](https://uk.finance.yahoo.com/news/alnylam-pharmaceuticals-alny-stock-looks-190632817.html?ref=bullished.co) — Yahoo Finance
- [Alnylam: Q3 Earnings Snapshot – WTOP News](https://wtop.com/national/2026/10/alnylam-q3-earnings-snapshot/?ref=bullished.co) — wtop.com
- [Alnylam Pharmaceuticals Non-GAAP EPS of $16.26 beats by $14.01, revenue of $1.46B beats by $30M (ALNY:NASDAQ)](https://seekingalpha.com/news/4660169-alnylam-pharmaceuticals-non-gaap-eps-of-16%5F26-beats-by-14%5F01-revenue-of-1%5F46b-beats-by-30m?ref=bullished.co) — seekingalpha.com
- [Alnylam Pharmaceuticals Q3 2026 Earnings Preview (NASDAQ:ALNY) | Seeking Alpha](https://seekingalpha.com/news/4659092-alnylam-pharmaceuticals-q3-2026-earnings-preview?ref=bullished.co) — seekingalpha.com
- [The company's filing (Alnylam Pharmaceuticals)](https://www.sec.gov/Archives/edgar/data/0001178670/000117867026000074/alny-20261029.htm?ref=bullished.co) — SEC filing
- [Alnylam Pharmaceuticals — Form 10-Q for the quarter ended 2026-09-30 (quarterly results)](https://www.sec.gov/Archives/edgar/data/1178670/000117867026000076/alny-20260930.htm?ref=bullished.co) — SEC EDGAR

### More on Alnylam Pharmaceuticals

- [Alnylam Will Skip 2027 Guidance At JPMorgan, Waiting On A Medicare 340B Rule](https://www.bullished.co/alnylam-will-skip-2027-guidance-at-jpmorgan-waiting-on-a-medicare-340b-rule-6932af0e/)
- [Alnylam CEO Says Company Is 'Not Yet Satisfied' With Amvutra Demand, Sees No Fourth-Quarter Acceleration](https://www.bullished.co/alnylam-ceo-says-company-is-not-yet-satisfied-with-amvutra-demand-sees-no-fourth-quarter-0fe809b3/)
- [Alnylam's $2.17 Billion Quarterly Profit Rests On A $1.87 Billion Tax Benefit](https://www.bullished.co/alnylams-2-17-billion-quarterly-profit-rests-on-a-1-87-billion-tax-benefit-5a51fde7/)

[All Alnylam Pharmaceuticals (ALNY) coverage →](https://www.bullished.co/tag/alny/)