Read the Change Log Before Rebuilding an Index
The Nasdaq-100 represents 100 of the largest eligible Nasdaq-listed non-financial companies. It is different from the Nasdaq Composite and does not include every Nasdaq listing. This page displays provider-reported membership events; it does not calculate index levels, portfolio weights, or returns.
Membership Changes and Weight Changes
Reconstitution concerns membership, while rebalancing concerns weights. The annual December reconstitution and quarterly rebalances can include overlapping changes. Nasdaq’s May 2026 update added rank-based membership reviews in March, June, and September, and an eligibility-based Fast Entry route for large new listings. A constituent can also leave following a corporate event.
Use Nasdaq’s explanation of the 2026 methodology update and the event’s official announcement to interpret a record. Do not apply today’s methodology retrospectively to older changes.
How to Use the Table
- The page requests available records automatically. Refresh requests them again; the service may reuse a cached response.
- Read the supplied added and removed identifiers. A dash means the provider did not supply that field, not that the event did not happen.
- Provider Date and Date Added preserve the upstream date fields. Confirm announcement and effective times separately before using a row in a time-sensitive analysis.
- Browse 20 rows per page. Export CSV includes every returned row, not just the visible page. It does not fetch omitted history.
What a Historical Universe Still Needs
Start from a verified membership at a known date, apply all changes at the correct effective times, and account for identifier changes, multiple share classes, and delistings. Prices, index weights, and corporate-action adjustments are separate inputs. This tool does not assemble or validate that universe for you.
In an invented example, a change announced Monday but effective Friday must not be treated as known on the prior Friday. The provider date alone does not establish when an investor could have acted. A membership change is also not a reliable prediction of the stock’s next return.
Coverage and Access
This page has no payment or account-entry form. It depends on Financial Modeling Prep’s service, access limits, and available history. Empty or failed responses are not evidence of no historical changes. There is no search filter, price forecast, or index-tracking backtest on this page.