Why Is ALNYLAM PHARMACEUTIC (ALNY) Stock Down Today?

ALNY stock fell 27.64% to $207.41 in early trading on July 30, 2026, driven by Alnylam Pharmaceuticals lowering its full-year revenue guidance amid headwinds in its ATTR-CM program. The company reported Q2 2026 results that missed revenue estimates and included a revised outlook reflecting slower-than-expected demand normalization. The sharp intraday decline followed a volatile open, with the stock falling below $210 within the first 35 minutes of trading.

What Happened

Alnylam Pharmaceuticals reported its Q2 2026 financial results on July 30, with adjusted earnings per share of $1.84, beating the $1.55 estimate. However, revenue of $1.291 billion fell short of the $1.323 billion forecast. The company also reduced its full-year sales guidance from $5.3 billion to $5.8 billion to $5.275 billion to $5.725 billion, citing ongoing challenges in the ATTR-CM market. The move signals a shift in expectations for the remainder of the year. Additionally, Alnylam highlighted progress in its neuroscience pipeline, including the launch of a Phase 2 study for mivelsiran in Down syndrome-associated Alzheimer’s. Despite these updates, the stock reacted negatively to the revised guidance and below-estimate revenue.

What The Data Shows

The stock opened at $287.00 and briefly touched a high of $288.15 before plunging to a session low of $206.00. Trading volume reached 2.6 million shares, more than double the 3-month daily average. The stock is now trading at a 21.3% discount to its 52-week high of $262.21. Recent insider activity includes one sale totaling $1.1 million by a director, while congressional trades show mixed activity from Donald J. Trump, including both purchases and sales in the $1,001 to $15,000 range over the past five months.

What To Watch

Alnylam Pharmaceuticals has no upcoming earnings report scheduled. Investors will likely monitor the breadth of analyst coverage and any further updates on the company’s ATTR-CM and neuroscience programs, particularly the progress of the APPlauDS and cAPPricorn-1 trials.