---
title: "JPX Prime 150: Methodology"
description: "JPX Prime 150 is maintained by JPX and covers selected prime market companies. How the index selects and weights its constituents."
canonical: https://www.getswoopr.com/stocks/indexes/jpx-prime-150/
source: "Swoopr Investment: https://www.getswoopr.com"
---

# JPX Prime 150: What It Measures and How It Is Built







## Direct Answer



> The JPX Prime 150 is a rule-based measurement of selected prime market companies, maintained by JPX. 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 JPX Prime 150 covers selected prime market companies, within the Japan market. JPX defines which securities are eligible, how they are selected from that pool, and how much each one contributes to the published number.



The name states a target of 150 companies. A target is not a guarantee of the exact count on any given day: corporate actions, dual share classes and pending additions all move the real number around it.








## How constituents are weighted



Swoopr has not verified the weighting method for this index against JPX's current methodology document, so none is stated here rather than guessed. The provider link below is authoritative.








## Current JPX Prime 150 constituents



JPX publishes and licenses the JPX Prime 150 constituent list. Swoopr does not republish it here. The provider's own page is the authoritative source for current membership and weights.



[JPX: official JPX Prime 150 page](https://www.jpx.co.jp/english/markets/indices/)








## Related reading



- [All stock market indexes](https://www.getswoopr.com/stocks/indexes/): how indexes are built, weighted and revised.
- [Asia-Pacific indexes](https://www.getswoopr.com/stocks/indexes/asia-pacific/): 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 JPX Prime 150?



JPX maintains the JPX Prime 150 and publishes the methodology document that defines its eligibility and weighting rules.




### What does the JPX Prime 150 measure?



It measures selected prime market companies. 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 JPX Prime 150 constituents?



JPX 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.