Rulebook · version 1.6
The complete methodology of the Index 9000: eligibility, constituent selection, weighting, maintenance between reviews, and calculation of the index level. Launched on 19 September 2026 with a base date of 31 December 1976; levels before the launch date are back-calculated.
The Index 9000 (the “Index”) is designed to measure the performance of the global listed equity market. The Index comprises the 9,000 largest eligible listed companies, weighted by market capitalisation. This document sets out the rules by which the Index is constructed, maintained and calculated. Where the rules are silent, no action is taken.
A security is eligible for inclusion if, at the review data date, all of the following are true.
Where a company has more than one eligible share class, each class is treated as a separate security and ranked on its own free-float capitalisation.
At each annual review the eligible universe is ranked by market capitalisation in US dollars. The index comprises the 9,000 highest-ranked securities, subject to the buffer in 3.2.
Between reviews, the constituent count may fall below 9,000 through removals under section 6. It is not restored until the next review.
Each constituent is weighted by its market capitalisation: price multiplied by shares in issue, converted to US dollars. No free-float adjustment is made, no cap is applied to any constituent, sector or market, and no constituent is weighted other than by its capitalisation.
Weights change with every price. Share counts are fixed at the annual review as capitalisation divided by price on the review data date, and change only on corporate actions under section 6.
The index is reviewed once a year. Data are taken as at the close of the last business day of August. Changes take effect after the close on the third Friday of September and are announced no later than the first business day of September.
The review updates constituents under section 3, and share counts and free-float factors for all constituents. There is no interim review and no provision for one.
Between reviews the following events are reflected, on their effective date, so that the event itself neither adds to nor subtracts from the index level.
No other event is reflected. In particular, changes in shares in issue arising from buybacks, option exercise and placings are reflected only at the annual review.
The Index is a total-return index. Cash dividends are reinvested, so that the level reflects both price movement and income. The Index is calculated every three minutes from the latest price on the primary listing of each constituent, and once a day at 22:15 UTC, after the last constituent market has closed, as the official close.
where p is the latest price, s the index shares, f the free-float factor (fixed at 1 since version 1.5), x the live exchange rate to US dollars, and D the divisor. The divisor is set at inception so that the level is 1,000.00 and is adjusted under section 6 so that corporate actions and constituent changes do not themselves move the level.
On a constituent's ex-dividend date the cash dividend, multiplied by its index shares and converted to US dollars, is treated as reinvested across the whole index: the divisor is reduced in the proportion of that cash to the index's value, so the level is unaffected by the price falling ex-dividend. Dividends are applied at the official close of the ex-date, or of the first close after the feed reports them. A dividend greater than half the share price is treated as a data fault and recorded in a notice.
Where a constituent has not traded on day t, its last traded price is carried. Where an exchange is closed, all of its constituents are carried. The level is published to two decimal places.
The base level of 1,000.00 was set at the close of 31 December 1976. The record to 18 September 2026 is a back-history computed from real market data on a total-return basis: the S&P 500 with its dividends to 1984, MSCI World and MSCI ACWI with dividends reinvested at the S&P 500's yield to mid-2008, and Vanguard's Total World Stock ETF (VT) with dividends reinvested to launch, each series chained to the next at the join and the whole rebased to 1,000.00 at 31 December 1976. From 19 September 2026 the index is calculated from its own constituents, with the divisor set on that day so that the level continued the back-history at 146,061.16. Historical levels are never restated; a correction to an input after publication is reflected in the next level through the divisor.
The Index did not exist before 19 September 2026. Levels before that date are back-calculated, are hypothetical, and would not have been available at the time.
The full monthly record is published on the History page.
The Index is administered privately. There is no index committee. This methodology is applied as written and provides for no discretion. Where circumstances arise that these rules do not address, no action is taken and the circumstances are recorded in a notice.
Revisions to this document are limited to corrections and clarifications. A change to constituent selection or to weighting is outside the scope of this document.
A constituent is recorded as tokenized where a token contract representing it is listed in the public asset registry published by Robinhood for Robinhood Chain. The registry is read daily; constituents are matched to it by security identifier and by company name, and the match is recorded on the Tokenization page and against the constituent.
Tokenization is a record, not a criterion. It has no effect on eligibility, selection, weighting or calculation, and no token is held, referenced or required by the Index.
Constituent lists, market capitalisations, prices and exchange rates are taken from public exchange feeds. Prices are real time or delayed by fifteen to twenty minutes according to the exchange. A constituent whose feed does not update is carried at its last price under section 7. Markets with no public feed are not carried; as at version 1.5 these are Egypt, Peru and the Philippines.
The four series of the back-history (section 8) are taken from the same source, with the S&P 500's monthly dividends from a published academic series. Dividends for constituents are taken from the feed's corporate-action records.
Where feed data is evidently incorrect, the constituent is carried at its last valid price and the error is recorded in a notice.
| Version | Date | Change |
|---|---|---|
| 1.6 | 19 Sep 2026 | Total return: dividends reinvested on the ex-date through the divisor (7); back-history restated with dividends (8). |
| 1.5 | 19 Sep 2026 | Live calculation from real data. Weighting by full market capitalisation (4); free-float test removed from eligibility (2); calculation every three minutes with an official close at 22:15 UTC (7); section 11 added. |
Versions before 1.5 were working drafts and were not published.