Shares of drugmaker Alnylam Pharmaceuticals ALNY.O fell 26.5% to $210.27.
The stock was on track for its biggest one-day percentage drop since October 2016, if losses hold.
The decline was set to wipe about $10 billion off Alnylam's market value, if losses hold, bringing its market cap down to around $28.1 billion.
As of the last close, the stock was down 27.9% year to date.
Quarterly results and analyst reaction
Alnylam reported second-quarter sales of $1.29 billion, below analysts' estimates of $1.32 billion, according to LSEG data.
The company reported adjusted EPS of $1.84, compared with estimates of $1.55.
Evercore ISI analysts said the results were "sure to drive a harsh knee jerk reaction" and the forecast cut adds "more uncertainty to the story" and could raise questions about Amvuttra's peak sales potential.
2026 revenue guidance lowered
The company trimmed its 2026 total net product revenue forecast to between $4.7 billion and $5.1 billion, from a prior view of $4.9 billion to $5.3 billion.
It also lowered its 2026 TTR product revenue forecast to between $4.2 billion and $4.5 billion, from $4.4 billion and $4.7 billion, citing slower growth for its flagship drug Amvuttra.
ALNY•
