The list in ChatGPT and Claude
The exclusion list is also an app that AI assistants can use. Asked whether a company is on the list, an assistant answers from the published list itself, with the screen’s reasons and a link back to it, rather than from memory.
Server address
https://purpleturtle.io/mcpNo account and no sign-in: it reads only the public list. Any assistant that connects to remote MCP servers can use this address; in Claude it is added as a custom connector.
What to ask
- “Is Intel on Purple Turtle's exclusion list?”
- “Which of Tesla, Apple and Exxon Mobil are on the Purple Turtle exclusion list?”
- “Which technology companies are on Purple Turtle's exclusion list?”
- “How is the Purple Turtle exclusion list made?”
What it can do
Check companies against the exclusion list
Up to 50 tickers or company names at a time: which are on the list, with the screen's reasons, and which are not.
List excluded companies by sector
How many companies on the list each sector has, or every company in one sector with its reasons.
How the exclusion list is made
The companies screened, the measures, when the list changes, what the research record shows and its caveats.
All three only read. The list covers the 500 largest US companies, minus banks, insurers and utilities; this one was set at the 31 July 2026 review and changes at the next.
What it does not do
It gives no ranks, scores or portfolio holdings, only the list and its reasons, and it gives no advice: every answer says it is general information from a published screen, not a personal recommendation, and names who publishes it. It cannot see the conversation, only the companies the assistant asks about, and nothing it is asked is stored.
Privacy and support
What the app receives and keeps is set out in the privacy notice. Questions and problems: hello@purpleturtle.io.
Required disclosures · producer, method, ratings, conflicts
- Producer
- Purple Turtle, a research publication produced in a personal capacity in Denmark. Not authorised or supervised by Finanstilsynet: general investment research published identically to every reader does not require authorisation. The legal person behind Purple Turtle is named in full on the terms page.
- Completed and first disseminated
- Ranking completed on 31 July 2026, using filings and prices available on that date — it cannot have used anything later. The books in this edition were built from that ranking under the revised method described on the method page, completed on 1 October 2026, and first published on 1 October 2026. They replace the books previously published for this ranking. The holdings, their weights are fixed until the next ranking on 31 January 2027. Share prices shown alongside them are refreshed daily and are not part of the ranking.
- Methodology
- The 500 largest US companies by market value, excluding financials and utilities, are ranked on four measures: cash return on assets, free cash flow against price, gross profit against assets, and days taken to file quarterly results (reversed). Ranks are added with equal weight. Three books are drawn from the top of the ranking, of 6, 12 or 20 companies; two of them also hold an exchange-traded fund that aims to return twice the daily return of the S&P 500, while a published trend rule is on. The bottom 250 are published as the exclusion list. No price targets are issued and no forecasts are made. Only accounts already filed with the regulator are used, plus 60 days. Full method.
- Rating scale and frequency
- Two ratings only: held (in the published book) and not held (removed). A company can be neither, and most are. There is no buy, sell or hold rating and no target price. Ratings are reviewed twice a year, in January + July, and do not change in between except where a company ceases to trade.
- Rating distribution
- Of the 500 companies covered this period: 50% held, 50% not held, and 0% neither — ranked above the exclusion line but outside this particular book.
- Holdings and conflicts
- The producer does not currently hold the published portfolios, and any position taken in a covered company will be disclosed with the ranking it concerns. No trade is made in any covered company from five trading days before publication to two trading days after. No position exceeds 0.5% of any issuer's share capital. No compensation of any kind has been received from any issuer, and no issuer has been shown this material before publication.
- Nature of this material
- General investment research, produced to a fixed method and published identically to every reader. It is not a personal recommendation: no assessment has been made of any reader's circumstances, objectives, or financial situation. Facts are distinguished from estimates throughout, and past performance does not predict future results. Your capital is at risk. Two of the books hold a leveraged fund, so their losses can be larger and come faster than the index's, and the fund's part of the backtested record is modelled from the index — calibrated to the real fund's record since 2010 — rather than taken from its market price.
- Availability
- Offered to residents of the EU, EEA and United States. Not offered to UK persons.