--- title: "BIST All Shares: Methodology" description: "BIST All Shares is maintained by Borsa Istanbul and covers broad Turkish equity benchmark. How it selects and weights its constituents, and what it measures." canonical: https://www.getswoopr.com/stocks/indexes/bist-all-shares/ source: "Swoopr Investment: https://www.getswoopr.com" --- # BIST All Shares: What It Measures and How It Is Built ## Direct Answer > The BIST All Shares is a rule-based measurement of broad Turkish equity benchmark, maintained by Borsa Istanbul. 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 BIST All Shares covers broad Turkish equity benchmark, within the Turkey market. Borsa Istanbul 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 Weighted by free float market value: number of shares times price times free float ratio times a weighting factor. No capping ratio is listed for this index, which is published in lira, dollars and euros as price and return versions. 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 All companies traded on the Stars, Main and SubMarket markets. Stocks on the Watchlist Market, Venture Capital Market and Pre Market Trading Platform, structured products, funds and the commodity market are excluded, and stocks of investment trusts are left out of every index except the BIST Investment Trusts index. 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 There is no waiting period: stocks that start trading for the first time are included in this index from their first trading day, unlike BIST 30, 50, 100 and 500 which wait for a periodic review. A suspended stock returns on the date trading restarts. 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 not in the periodic review table: membership follows market segment and trading status. A stock transferred to the Watchlist Market, suspended for more than five consecutive trading days, or permanently halted leaves on that date. 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 It is a coverage index with no ranking or size cut off, and the BIST All Shares 100 index is simply the stocks in the All Shares index that are not in the BIST 100. ## References - [Borsa Istanbul: Borsa Istanbul, BIST Market Cap Weighted Stock Indices Methodology, September 2026 edition](https://borsaistanbul.com/files/bist-mcw-equity-indices-m-eng-202609-clean.pdf), as published 2026. Every rule described on this page is taken from this document. ## Current BIST All Shares constituents Borsa Istanbul publishes and licenses the BIST All Shares constituent list. Swoopr does not republish it here. The provider's own page is the authoritative source for current membership and weights. [Borsa Istanbul: official BIST All Shares page](https://www.borsaistanbul.com/en/sayfa/2316/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 BIST All Shares? Borsa Istanbul maintains the BIST All Shares and publishes the methodology document that defines its eligibility and weighting rules. ### What does the BIST All Shares measure? It measures broad Turkish equity benchmark. 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 BIST All Shares constituents? Borsa Istanbul 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.