--- title: "NSE All Share Index (Kenya): Methodology" description: "NSE All Share Index (Kenya) covers all companies listed on the Nairobi Securities Exchange weighted by market capitalisation. How it is weighted." canonical: https://www.getswoopr.com/stocks/indexes/nse-all-share/ source: "Swoopr Investment: https://www.getswoopr.com" --- # NSE All Share Index (Kenya): What It Measures and How It Is Built ## Direct Answer > The NSE All Share Index (Kenya) is a rule-based measurement of all companies listed on the Nairobi Securities Exchange weighted by market capitalisation, maintained by Nairobi Securities Exchange. 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 NSE All Share Index (Kenya) covers all companies listed on the Nairobi Securities Exchange weighted by market capitalisation, within the Kenya market. Nairobi Securities Exchange 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 Base weighted aggregate (market capitalisation) method: total market value at current prices, shares outstanding times price, divided by the base market value and applied to a base level of 100. A divisor absorbs corporate actions. No free float adjustment is described. 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 Any ordinary share listed on the Main Investments Market Segment or the Alternative Investment Market Segment, all classes of ordinary shares included, with local and cross listed foreign companies both counted. The rules state no limits on size, liquidity or free float. 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 stock joins on its first day of listing, priced at that day's volume weighted average price. 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 The index is updated after the close of each trading session. A review in the last week of every calendar quarter tracks changes in shares outstanding and adjusts the divisor. 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 The index has no size, liquidity or free float screens at all, so thinly traded and closely held companies count at full market value from their first trading day. ## References - [Nairobi Securities Exchange: Nairobi Securities Exchange, Ground Rules for Generation of NSE All Share Index](https://www.nse.co.ke/wp-content/uploads/ground-rules-nse-all-share-index.pdf), as published 2019. Every rule described on this page is taken from this document. ## Current NSE All Share Index (Kenya) constituents Nairobi Securities Exchange publishes and licenses the NSE All Share Index (Kenya) constituent list. Swoopr does not republish it here. The provider's own page is the authoritative source for current membership and weights. [Nairobi Securities Exchange: official NSE All Share Index (Kenya) page](https://www.jse.co.za/services/market-data/indices) ## Related reading - [All stock market indexes](https://www.getswoopr.com/stocks/indexes/): how indexes are built, weighted and revised. - [Emerging Markets indexes](https://www.getswoopr.com/stocks/indexes/emerging-markets/): 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 NSE All Share Index (Kenya)? Nairobi Securities Exchange maintains the NSE All Share Index (Kenya) and publishes the methodology document that defines its eligibility and weighting rules. ### What does the NSE All Share Index (Kenya) measure? It measures all companies listed on the Nairobi Securities Exchange weighted by market capitalisation. 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 NSE All Share Index (Kenya) constituents? Nairobi Securities Exchange 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.