How Is the Nasdaq-100 Weighted?

Larger market values generally carry greater weight

A market-cap-weighted index starts from the market value of its constituents. A modified method then applies additional rules described by the index provider. For the Nasdaq-100, these rules mean the final constituent weights are not simply each company's raw market capitalization divided by the total.

The exact eligibility, market-cap measurement, weighting, adjustment, and rebalance rules are defined in Nasdaq's current methodology. Those rules can change, so consult the current document for implementation details.

The index and QQQ are related, but different

QQQ is an exchange-traded fund designed to track the Nasdaq-100. Its portfolio holds securities to track the index, but ETF weights can differ from official index weights because of fund structure, cash, expenses, trading, and timing.

Market Watch 360's dated QQQ holdings are used as an accessible weight reference. The site's 76.05% top-30 figure is explicitly QQQ net-asset coverage from that holdings snapshot, not a claim of exact official Nasdaq-100 index coverage.

Why concentration still matters

Even with weighting rules and limits, large constituents can have more influence than smaller ones. The top 30 securities offer a focused view of important leaders, while the remaining constituents can still affect the index.

A top-30 display is therefore a partial market lens. It can help explain selected contributors; it does not recreate the complete NDX calculation.

Read weights and market data with dates

A holdings snapshot and an index close may refer to different moments. Check the date and source attached to each figure, and treat illustrative charts as illustrations unless a verified historical price series is explicitly identified.