Alnylam Pharmaceuticals (ALNY) Stock on Dec. 22, 2025: Nasdaq-100 Debut, AMVUTTRA Momentum, Analyst Price Targets and the 2026 Outlook

Dec. 22, 2025 — Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY) is stepping into a new tier of market visibility today as its Nasdaq-100 Index membership takes effect ahead of the opening bell—an index catalyst that can influence near-term trading and broaden long-term institutional ownership. ^[1]

ALNY was trading around $405.60 on Dec. 22 (time-stamped 16:37 UTC), up about 1.3% versus the prior close—an incremental move that nonetheless lands in the middle of a busier-than-usual news cycle for the RNAi leader.

Below is a comprehensive roundup of the current news, forecasts, and market analysis circulating through Dec. 22, 2025, and what investors are watching next.

What’s moving ALNY today

Three themes dominate ALNY coverage on Dec. 22, 2025:

Index catalyst: ALNY is now officially part of the Nasdaq-100, alongside other new additions in this year’s annual reconstitution. ^[2]
Commercial execution: Strong adoption of AMVUTTRA (vutrisiran) in transthyretin amyloidosis—especially the cardiomyopathy (ATTR-CM) launch trajectory—has been the central fundamental driver behind 2025’s rerating. ^[3]
Operational scaling: A newly announced $250 million U.S. manufacturing expansion is designed to increase capacity and lower production costs, which matters as Alnylam pushes beyond rare diseases toward broader indications. ^[4]

Nasdaq-100 inclusion: why it matters for ALNY stock

Nasdaq’s annual reconstitution—effective prior to market open on Monday, Dec. 22, 2025—adds Alnylam to a benchmark followed by a large ecosystem of passive and derivative products. ^[5]

Two details help explain why this headline can matter even if it doesn’t instantly change Alnylam’s fundamentals:

Passive demand can rise. Index inclusion typically increases required ownership by funds tracking the Nasdaq-100, which can translate into incremental buying around reconstitution. MarketWatch noted that index inclusion benefits companies through increased demand from funds tracking the Nasdaq-100. ^[6]
The Nasdaq-100’s footprint is large. Nasdaq says that as of Dec. 2025, the Nasdaq-100 underpins 200+ tracking products with over $600 billion in assets under management, including Invesco QQQ. ^[7]

Who was added and removed? Nasdaq’s published list shows six additions (including Alnylam) and six removals, with the changes taking effect today. ^[8]

Investor takeaway: Nasdaq-100 membership doesn’t make a company “better,” but it can expand the shareholder base, potentially tighten spreads over time, and heighten visibility among large allocators who benchmark to major indexes.

The fundamentals behind ALNY’s 2025 rally: AMVUTTRA and the TTR franchise

A major reason ALNY is even eligible for Nasdaq-100 inclusion is straightforward: the company has been delivering a scale story—commercially and clinically—built around transthyretin (TTR) amyloidosis.

In its Q3 2025 update, Alnylam reported:

Total net product revenues of $851 million for Q3 2025, cited as 103% growth year-over-year. ^[9]
Total TTR net product revenues of $724 million, including AMVUTTRA $685 million and ONPATTRO $39 million in the quarter. ^[10]
A raised 2025 outlook, with updated guidance for total net product revenues of $2.95 billion to $3.05 billion, described as a $275 million / 10% increase at the midpoint (and TTR franchise net revenues of $2.475 billion to $2.525 billion). ^[11]

This is why so much of the 2025 investor narrative has centered on AMVUTTRA’s ATTR-CM trajectory and the durability of uptake across patient segments. ^[12]

Dec. 2025 news roundup: manufacturing scale, global approvals, and next-gen delivery

1) Alnylam’s $250 million manufacturing expansion

Alnylam announced it plans to invest $250 million to expand its Norton, Massachusetts facility and add an enzymatic ligation platform—positioned as a way to expand capacity and reduce production costs as demand grows and the pipeline broadens. ^[13]

Key details highlighted in the company’s announcement include:

The investment supports what Alnylam describes as a dedicated, proprietary siRNA enzymatic-ligation facility. ^[14]
The platform (siRELIS™) has been accepted into the FDA’s Emerging Technology Program, intended to accelerate regulatory engagement around innovative manufacturing approaches. ^[15]

Fierce Pharma added an operational timeline detail—saying the new capabilities are expected to come online by late 2027—and connected the manufacturing bet to Alnylam’s push toward larger-population diseases over time. ^[16]

Why investors care: For complex modalities like oligonucleotides, manufacturing isn’t just a cost line—it can be a strategic constraint. If Alnylam’s next phase requires higher volumes (and potentially broader indications), scaling production efficiently becomes a competitive differentiator, not just an efficiency project.

2) Health Canada approval expands AMVUTTRA’s footprint

In Canada, Alnylam’s subsidiary announced Health Canada issued a Notice of Compliance authorizing AMVUTTRA (vutrisiran) for treatment of cardiomyopathy in adult patients with wild-type or hereditary ATTR amyloidosis, describing it as the first and only RNAi therapeutic authorized in Canada for both cardiomyopathy manifestations and certain polyneuropathy stages. ^[17]

Why it matters: Every incremental geography and label expansion contributes to the longer-term revenue curve—and can influence investor confidence in the global standard-of-care trajectory.

3) PeptiDream milestone targets delivery beyond the liver

Alnylam’s collaboration ecosystem also produced noteworthy December momentum. PeptiDream announced a milestone with Alnylam demonstrating peptide-ligand mediated targeted siRNA delivery to specific extrahepatic tissues—a longstanding challenge for RNAi modalities that have historically been most effective with liver targeting. ^[18]

The announcement describes robust and specific uptake and target knockdown in animal models with subcutaneous administration, framing it as a step toward a modular delivery platform beyond liver-focused approaches. ^[19]

Why investors care: Delivery innovation can be a pipeline multiplier. If Alnylam can expand RNAi into additional tissues reliably, the addressable market opportunity could broaden over the next decade—though milestones are early, and translation to human outcomes takes time.

4) Governance and capital structure updates

Alnylam also announced board changes in early December, including the departures of Mike Bonney and Carolyn Bertozzi (effective Dec. 2, 2025) and the appointment of Stuart Arbuckle as a new independent director effective Jan. 5, 2026. ^[20]

On the balance sheet side, Alnylam disclosed privately negotiated agreements to repurchase about $34.4 million aggregate principal amount of its 1.00% convertible senior notes due 2027 for a total repurchase cost of approximately $51.9 million, with about $362.8 million principal remaining outstanding after closing. ^[21]

Why investors care: These updates speak to institutional maturity—governance refresh plus ongoing capital structure management—at the same time the company is scaling commercial operations and upgrading manufacturing.

ALNY forecasts: what Wall Street expects as of Dec. 22, 2025

Consensus view: “Moderate Buy,” with a high-teens implied upside

Aggregated analyst data tracked by MarketBeat shows:

Consensus rating: “Moderate Buy” ^[22]
Consensus price target: about $477.44 ^[23]

Against a price around the low-$400s on Dec. 22, that implies roughly high-teens upside—but importantly, that’s a consensus average, not a promise. ^[24]

MarketBeat also lists earnings expectations improving, showing earnings expected to grow in the coming year (from ($1.70) to $0.89 per share, per its summary metrics). ^[25]

Recent notable analyst moves in December

Two widely circulated price-target updates show how divided the debate can be around valuation vs. growth durability:

Stifel raised its target to $508 (from $495) and reiterated a “buy” rating (as reported via MarketBeat’s roundup). ^[26]
Leerink Partners cut its target to $351 (from $370) with a “market perform” rating (also via MarketBeat’s roundup). ^[27]

How to read this spread: The range reflects different assumptions about (1) AMVUTTRA’s sustainable penetration in ATTR-CM, (2) pricing and competitive dynamics in amyloidosis, and (3) how much value to assign to earlier pipeline optionality and next-gen delivery breakthroughs.

ALNY stock snapshot on Dec. 22, 2025: price levels investors are watching

As of Dec. 22, MarketBeat’s key stats page indicated:

Market cap: roughly $53–54 billion ^[28]
52-week range: about $205.87 to $495.55 ^[29]
Year-to-date move: MarketBeat calculated ALNY up about 72.8% in 2025 (from ~$235.31 to ~$406.65). ^[30]

The high-level picture: ALNY is no longer a “small biotech” story; it’s being valued like a large, index-grade growth pharma/biotech—with the expectations (and scrutiny) that come with that status.

Key risks and open questions (what serious investors keep on the checklist)

Even with an index catalyst and strong commercial momentum, ALNY remains a biotech stock—and that means risk is part of the package.

1) Regulatory and legal overhangs

In its Q3 2025 release, Alnylam disclosed it received a subpoena from the U.S. Attorney’s Office for the District of Massachusetts seeking documents related to government price reporting and certain fee/discount arrangements with distributors. ^[31]

2) Growth concentration

AMVUTTRA is the core engine of the current rerating. Any sign of slower-than-expected new patient adds, payer friction, competitive displacement, or pricing pressure can ripple through the valuation quickly.

3) Manufacturing execution risk

Alnylam is taking on ambitious manufacturing innovation—explicitly aiming for greater throughput and lower cost. That’s strategically attractive, but execution and regulatory alignment matter, especially as new processes scale toward commercial volumes. ^[32]

4) Pipeline timing

Alnylam’s Q3 update also pointed to upcoming pipeline milestones—such as initiation timing and partner regulatory plans—which can shift with clinical realities and regulator feedback. For example, the company highlighted plans around a Phase 2 Alzheimer’s study (mivelsiran) and referenced Regeneron’s expectation to submit cemdisiran for FDA approval in Q1 2026 (pending discussion). ^[33]

Bottom line: what the Dec. 22, 2025 setup means for ALNY investors

ALNY’s Nasdaq-100 inclusion is a real trading catalyst and an institutional milestone—but it’s ultimately a second-order effect. The first-order story remains the same:

AMVUTTRA’s commercial trajectory and the broader TTR franchise are driving revenue scale and raised guidance. ^[34]
The company is investing to remove manufacturing constraints and potentially improve long-run margins and capacity as demand expands. ^[35]
Analysts remain broadly constructive on the stock with a consensus target above current levels, but the dispersion in price targets shows the market is still debating how much growth durability is already priced in. ^[36]