Nasdaq-100 Portfolio Gets Major Shake-Up: Six Companies In, Six Others Out Before Year-End Trading

The Nasdaq has unveiled significant changes to its flagship Nasdaq-100 Index, reshuffling the portfolio ahead of the final trading week of 2025. Beginning December 22, the exchange will welcome six fresh members while simultaneously delisting the same number of existing constituents, marking a meaningful shift in the index’s composition.

New Entrants to the Index

The incoming companies bring diverse sector exposure to the Nasdaq-100. Alnylam Pharmaceuticals (ALNY), a player in the pharmaceutical space, joins alongside Ferrovial SE (FER), Insmed Inc. (INSM), and Monolithic Power Systems (MPWR). The reconstitution also brings in two prominent technology-hardware names: Seagate Technology Holdings (STX) and Western Digital Corp. (WDC), both integral to the storage and data solutions sector.

Companies Departing the Index

On the flip side, six established members are being removed from the benchmark. These departing constituents include Biogen Inc. (BIIB), CDW Corporation (CDW), GlobalFoundries Inc. (GFS), Lululemon Athletica (LULU), ON Semiconductor Corporation (ON), and The Trade Desk Inc. (TTD). This exit of others represents a notable shift, particularly given the presence of established names like Biogen and Lululemon.

What This Means for Investors

Annual index reconstitutions are routine market events, yet they carry tangible implications for portfolio managers tracking the Nasdaq-100. The addition of Seagate and Western Digital underscores the index’s emphasis on semiconductor and hardware infrastructure, while the removal of others signals a recalibration of sector weightings. These changes take effect prior to Monday’s market open, giving traders and fund managers the weekend to prepare their positions accordingly.