Nasdaq-100 2025 Adds & Deletes Analysis

James Sterling December 18, 2025 2 min read

Nasdaq-100 Index 2025 Reconstitution Changes

Index funds typically trade infrequently, but they must adjust during index reconstitutions to align with the index’s updated composition.

These periodic updates ensure the index maintains its intended focus, such as emphasizing large-cap stocks, adjusting share floats, or reclassifying companies based on recent financial metrics. During reconstitutions, indexes implement additions, deletions, and various other modifications.

Index-tracking funds replicate these exact changes simultaneously, which can generate substantial trading volumes.

Numerous indexes schedule reconstitutions at consistent intervals throughout the year. This Friday marks a key date, with Nasdaq, FTSE, S&P, and Russell all announcing updates.

Our analysis centers on the Nasdaq-100 Index (NDX), examining its modifications for this event and historical patterns.

2025 NDX Reconstitution Features 12 Key Changes

The Nasdaq-100 undergoes an annual reconstitution each December, incorporating major new entrants while removing smaller constituents to preserve its 100-company limit.

For 2025, six newcomers join the index, boasting a combined market capitalization of approximately $300 billion. These additions have experienced over 50% growth in the past year, with several exceeding 100% expansion. Even the smallest addition holds a $48 billion valuation.

To balance the roster, six current members face removal. Notably, the largest deletion by market cap, BIIB at $27 billion, actually grew over the year but failed to keep pace sufficiently.

Market observers project roughly $50 billion in trading volume from this reconstitution, equating to more than 11% two-way turnover within the index portfolio.

Intra-Year Additions and Deletions Also Occur

Indexes with fixed company counts, such as the Nasdaq-100 and S&P 500, perform ad-hoc additions and deletions beyond the annual schedule.

Historical data reveals the Nasdaq-100 experiences numerous such changes outside December (depicted in light green and light red on the chart).

Over the last decade, patterns show approximately six official December changes and three off-cycle adjustments annually, positioning this year as typical.

Triggers for Off-Cycle Changes

Under Nasdaq-100 methodology, off-cycle additions primarily stem from deletions, except in cases like corporate spin-offs.

Potential deletion triggers encompass delisting, liquidation, exchange transfers (excluding Nasdaq), reclassification to ineligible types or Financials per ICB standards, or sustaining below 0.10% weight for two months.

Replacements involve the highest-market-cap eligible Nasdaq-listed security.

The following table illustrates recent off-cycle events and their causes:

Trading Volume from Index Adjustments

Beyond special rebalances, annual reconstitutions drive the bulk of turnover. The chart below delineates two-way turnover from ad-hoc changes (light green), quarterly rebalances (gray), annual events (dark green), and specials (gold).

Ad-hoc shifts, often involving smaller entities, yield lower annual turnover compared to reconstitutions.

While ad-hoc events usually produce under 1% turnover—akin to routine rebalances—occasional spikes occur, such as Kraft replacing Ctrip in 2012, Tesla supplanting Oracle in 2013 amid Oracle’s NYSE move, or Pepsi entering after listing on Nasdaq in 2018.