Alnylam Stock Plummets on Revenue Guidance Cut and Securities Law Probe

Key Facts

1Alnylam Pharmaceuticals lowered its 2026 sales guidance for TTR products by approximately $200 million.

2Law firm Kirby McInerney LLP launched an investigation into potential federal securities law violations.

3Jefferies analysts set a price target of $230.00 following the decline in the company's market value.

In a move reflecting shifting growth expectations in the biotech sector, Alnylam Pharmaceuticals saw its shares tumble after lowering its 2026 sales guidance for TTR products by approximately $200 million. According to reports, management attributed the revision to a demand slowdown following an initial surge. Compounding the financial pressure, law firm Kirby McInerney LLP has launched an investigation into potential federal securities law violations by the company or its leadership following a sharp decline in market value.

The downward revision has prompted analysts at Jefferies to set a price target of $230.00, suggesting further potential downside from recent levels. Per market data, the instrument 0HD2.L stood at $234.01 at close August 27, 2026, having traded within a range that reached a low of $231.17 during the same session. This bearish trend stands in contrast to broader sector performance, with the stock losing roughly a quarter of its valuation since late July.

Investors are now watching the $231.17 support level (as of August 27, 2026) to see if the sell-off intensifies. While the upcoming economic calendar shows no direct biotech catalysts, the focus remains on the legal probe's findings and the company's ability to stabilize its revenue outlook. The current price remains just above the Jefferies target, indicating a cautious sentiment among institutional observers.