Many indices are the same basket repackaged: quoted in another currency, as a price, total-return or net-return version, or currency-hedged. We group those lookalikes together. Purity is 100 divided by the size of the group: a one-of-a-kind index scores 100 (Pure), 2 to 6 lookalikes is Common, and 7 or more is Crowded. It measures uniqueness only, not quality or performance.
Two listings count as lookalikes when they come from the same provider and their names match once currency codes, return types (price, gross, net, total return), hedging words and filler such as "Index" are removed. Nasdaq's own symbol families (for example ^NDX, ^NDXEUR, ^NDXAUDMH) and ETF reference values that share a ticker (^PYZ-EU, ^PYZ-IV…) are also joined. Names cut off at 31 characters need a matching symbol pattern too, so different products with the same truncated name are not merged.
An index is a Eureka find when it is the only one of its category on an exchange, or in a region, that lists at least 25 distinct baskets. Finds are ranked by how busy that stream is. A find is unusual, not better: it is a starting point for reading, not a pick.
Membership is switched off here, so every feature is open to everyone.
Turn the screw lifts any slice of the atlas (an exchange, a currency, a region, a category group, a category or a provider) through six stages:
Lift is a 0–100 score for how unusual a basket is in the atlas. 35 points come from Purity (no lookalike copies scores full marks), 35 from how thin its square is (the fewer distinct baskets share its exchange and category, the higher), 15 from provider variety (full marks when no other basket from the same provider sits in that square) and 15 from how well it is described (a summary, and a known region). Baskets at 60 or more pass the assay. Lift measures uniqueness and coverage only. It says nothing about quality or performance, and it is not a reason to buy anything.
A basket passes the assay at a Lift of 60 or more, and the top 25 come out as nuggets. Squares are counted across the whole atlas, not only inside your intake. Lift measures uniqueness and coverage only. It says nothing about quality or performance, it is not a signal to buy anything, and nothing here is investment advice.
Saved intakes live in your browser. A saved intake older than a week is flagged for a re-run the next time you open the page; nothing runs in the background and nothing is emailed.
Index list from FinanceDatabase by Jeroen Bouma, released under the MIT License (Copyright © 2023 Jeroen Bouma). We use database/indices.csv at commit e5e2ecb, keep 75,627 equity-linked listings (bond, currency, commodity and cash indices are dropped) and add our own guesses for provider and region.
Educational reference only. Not investment advice.