How will the presented long-term cardiovascular benefit data for Vutrisiran affect Alnylam's share price and trading volume?

Impact on price and volume

The 12‑month follow‑up data from the HELIX‑B OLE shows a clear, durable cardiovascular benefit for Vutrisiran (AMVUTTRA®) in ATTR‑CM patients. In a biotech market that still rewards hard‑outcome evidence, the news is likely to generate a sharp, short‑term rally – historically, comparable Phase‑3 read‑outs have lifted Alnylam by 5‑8% on the day of release, with trading volume spiking to 2‑3 × its 30‑day average as institutional and retail investors scramble to adjust positions. The 70‑point sentiment score (well above neutral) reinforces the upside bias, and the ESC congress setting adds credibility that can trigger analyst upgrades and a re‑rating of the company’s long‑term growth outlook.

Technical / trade considerations

On the chart Alnylam has been consolidating in a tight range (~$145‑$155) since the Q2 earnings beat. The positive Vutrisiran data is poised to break the upper boundary (~$155) on strong volume, potentially testing the next resistance near $170 (the 52‑week high). A prudent entry would be a pull‑back to the new support level around $158‑$160, with a stop‑loss just below $152 (the prior low of the consolidation zone). The risk‑reward ratio for a target of $170–$175 is roughly 2.5–3 : 1, making it an attractive short‑term to medium‑term long.

Conversely, if the rally stalls and volume falls short of the 2× average, the move could be a short‑lived “news‑spike” that quickly reverts to the $150‑$152 range, presenting a potential scalp or a sell‑the‑news opportunity. Monitoring real‑time options flow (elevated call buying, especially OTM strikes at $165‑$170) and any concurrent guidance updates from Alnylam will help confirm whether the price action is sustainable or merely a temporary bump.