Up Over 200% YTD! AI Ignites Storage Boom – Seagate and Western Digital Both Join Nasdaq 100

On Friday local time, Nasdaq announced the annual rebalance for the Nasdaq 100 Index, adding six companies effective before the open on Monday, December 22, 2025.

 

The six companies joining the Nasdaq 100 are: Alnylam Pharmaceuticals, Ferrovial, Insmed, Monolithic Power Systems, Seagate Technology, and Western Digital.

 

 

Among them, Seagate Technology and Western Digital — both global leaders in storage solutions — entering the index highlights the storage sector’s red-hot momentum.

 

Meanwhile, six companies will be removed from the Nasdaq 100: Biogen Inc., CDW Corporation, GlobalFoundries Inc., Lululemon Athletica Inc., ON Semiconductor Corp., and The Trade Desk Inc.

 

Year-to-date, ad-tech firm The Trade Desk and athletic apparel retailer Lululemon are down ~70% and 45%, respectively — the two worst performers in the Nasdaq 100.

 

In contrast, all newly added companies have posted at least double-digit gains in 2025. Seagate Technology and Western Digital are both up over 200%, driven primarily by the AI-fueled storage supercycle.

 

Seagate Technology is a global leader in hard disk drives (HDD) and data storage solutions, with products widely used in data centers, cloud computing, PCs, and consumer electronics. Its shares have risen over 230% this year.

 

Western Digital offers a full range of data storage solutions including HDD and SSD, serving data centers, consumer electronics, and other scenarios. Its shares are up nearly 280% this year.

 

The Nasdaq 100 consists of the 100 largest non-financial companies listed on Nasdaq, heavily weighted toward tech and growth sectors. There is no minimum market-cap requirement for inclusion, but stocks must meet criteria such as average daily trading volume of at least 200,000 shares.

 

For newly added companies, inclusion in the Nasdaq 100 brings tangible benefits like fund inflows and improved liquidity, as many large passive funds (e.g., the $409 billion Invesco QQQ Trust Series 1 ETF) must hold all index constituents.