--- title: "MSCI World ex USA: Methodology" description: "MSCI World ex USA is maintained by MSCI and covers large- and mid-cap equities across 22 developed market countries excluding the United States." canonical: https://www.getswoopr.com/stocks/indexes/msci-world-ex-usa/ source: "Swoopr Investment: https://www.getswoopr.com" --- # MSCI World ex USA: What It Measures and How It Is Built ## Direct Answer > The MSCI World ex USA is a rule-based measurement of large- and mid-cap equities across 22 developed market countries excluding the United States, maintained by MSCI. Like every index it owns nothing: it is a number produced by applying a published weighting formula to a selected list of companies, revised on a schedule the provider sets. ## What this index covers The MSCI World ex USA covers large- and mid-cap equities across 22 developed market countries excluding the United States, within the Global market. MSCI defines which securities are eligible, how they are selected from that pool, and how much each one contributes to the published number. The index name does not state a fixed company count, so the number of constituents follows the eligibility rules rather than a target. ## How constituents are weighted Weights follow the free float-adjusted market capitalization of each constituent. The index is a regional composite created from the developed market indexes with the USA market index left out, using the same building block approach as MSCI World. The weighting method is the single biggest driver of how an index behaves. Two indexes covering the same market can diverge for years purely because they weight differently, which is why comparing index levels without knowing the method tells you very little. ## What qualifies for inclusion MSCI cites World ex USA as an example of a regional index formed by excluding specific markets from a composite. Every remaining constituent still passes the developed market screens: equity universe size, free float-adjusted market cap, a foreign inclusion factor of at least 0.15, and 20% ATVR with 90% three month frequency of trading. Eligibility rules are the part of an index most readers never look at and the part that decides what it can possibly measure. A screen that excludes a whole sector, or admits only one listing venue, shapes the result far more than any day of trading does. ## How long a listing must exist first A new issue must have started trading at least three months before the implementation of an Index Review to be eligible. Significantly large IPOs and large offerings by non-constituents are exempt and may be added outside a review, after the close of the company's tenth day of trading. A seasoning rule is why a large new listing does not appear in an index the week it starts trading. It is a deliberate lag, and it means an index can under-represent a fast-growing part of the market for months at a time. ## When the membership is revised Index Reviews are quarterly, in February, May, August and November, and each one is a full reassessment: the equity universe is refreshed, size cutoffs and buffer zones are reapplied, and foreign inclusion factors and share counts are updated. Results are announced at least two weeks ahead and generally take effect at the close of the last business day of the review month. Prices come from any one of the last 10 business days of the prior month. Reconstitution is the one date an index changes shape by design rather than by price. Funds tracking it have to trade toward the new membership, which is why the schedule matters to anyone holding the tracker rather than only to the provider. ## The rule that surprises people Indexes are built market by market from a global developed universe that includes the USA, so World ex USA is a subset of MSCI World. Size cutoffs and the 85% coverage target are set inside each market, so leaving out the USA does not change which companies qualify elsewhere. ## References - [MSCI: MSCI, MSCI GIMI Methodology: Index Construction Objectives, Guiding Principles and Methodology for the MSCI Global Investable Market Indexes](https://www.msci.com/index/methodology/latest/GIMI), as published 2026. Every rule described on this page is taken from this document. ## Current MSCI World ex USA constituents MSCI publishes and licenses the MSCI World ex USA constituent list. Swoopr does not republish it here. The provider's own page is the authoritative source for current membership and weights. [MSCI: official MSCI World ex USA page](https://www.msci.com/indexes) ## Related reading - [All stock market indexes](https://www.getswoopr.com/stocks/indexes/): how indexes are built, weighted and revised. - [Global indexes](https://www.getswoopr.com/stocks/indexes/global/): others covering the same region. - [Index concentration](https://www.getswoopr.com/technical-analysis/market-concentration/index-concentration/): measuring how much of an index sits in its largest holdings. - [Index rebalancing and inclusion effects](https://www.getswoopr.com/stocks/corporate-actions-catalysts/index-rebalancing-and-inclusion-effects/): what happens to a stock when index membership changes. ## Frequently Asked Questions ### Who maintains the MSCI World ex USA? MSCI maintains the MSCI World ex USA and publishes the methodology document that defines its eligibility and weighting rules. ### What does the MSCI World ex USA measure? It measures large- and mid-cap equities across 22 developed market countries excluding the United States. The index is a calculated number applying a weighting formula to a selected list of companies, and it holds nothing itself. ### Where can I see the current MSCI World ex USA constituents? MSCI publishes the current constituent list. Swoopr does not republish it, because index providers license constituent data and Swoopr holds no such licence. ## About the author The [Swoopr Editorial Team](https://www.getswoopr.com/authors/swoopr-editorial-team/) writes Swoopr Investment's educational library, covering market structure, analysis methods and the mechanics behind the numbers investors read every day. Our [editorial policy](https://www.getswoopr.com/legal/editorial-policy/) and [corrections policy](https://www.getswoopr.com/legal/corrections-policy/) set out how this content is produced, reviewed and fixed when it is wrong.