Archive · 22 Dec 2025
Six Stocks Join Nasdaq-100 with Up to 250% Gains
Six companies with big stock gains, up to 250% in a year, are joining the Nasdaq-100 Index.
This index tracks the top 100 non-financial companies on the Nasdaq.
The new companies include Alnylam, Ferrovial, Insmed, Monolithic Power Systems, Seagate Technology, and Western Digital.
They replace six other companies that are being removed.
The Nasdaq-100 is important because it supports over $600 billion in investments and many financial products.
The changes will happen before the market opens on December 22, 2025.
Six companies with stock gains up to 289% will join the Nasdaq-100 Index on December 22, 2025.
The new additions are Alnylam, Ferrovial, Insmed, Monolithic Power Systems, Seagate Technology, and Western Digital.
The Nasdaq-100 Index tracks the performance of the 100 largest non-financial companies on the Nasdaq.
Six companies, including Biogen and Lululemon, will be removed from the index.
The Nasdaq-100 underpins over $600 billion in assets under management globally.
- Who
- Nasdaq
- What
- Annual reconstitution of the Nasdaq-100 Index
- When
- Effective December 22, 2025
- Where
- Nasdaq Stock Market
- Why
- To reflect the performance of the largest non-financial companies
- Effective Date
- December 22, 2025
- New Additions
- Alnylam, Ferrovial, Insmed, Monolithic Power, Seagate, Western Digital
- Removed Companies
- Biogen, CDW, GlobalFoundries, Lululemon, ON Semiconductor, The Trade Desk
- Index Assets
- $600 billion
- Alnylam's Gain
- 65%
- Ferrovial's Gain
- 58%
- Insmed's Gain
- 147%
- Monolithic Power's Gain
- 51%
- Seagate's Gain
- 234%
- Western Digital's Gain
- 289%