By Tim du Toit, founder of Quant Investing. 39 years investing experience since 1987. Published: 18 May 2026. Last updated: 18 May 2026.
Quant Investing MCP, definition:
A Model Context Protocol server published by Quant Investing in May 2026 that lets Claude AI call 32 tools across the live stock screener (24,000 companies), the Quant Value newsletter archive (since 2010), the Shareholder Yield Letter archive (since May 2023), the subscriber's own watchlists and saved screens, and a full backtesting engine. Included with the Best Deal subscription.
Quant Investing today announces that subscribers to its top-tier Best Deal plan can now connect Anthropic's Claude AI directly to the Quant Investing screener database, both monthly investment newsletters, and a full historical backtesting engine.
The service uses the Model Context Protocol (MCP), an open standard published by Anthropic in November 2024 that lets large language models call structured tools on remote servers. Quant Investing is one of the first stock screening services in the world to combine such a connection with a working backtesting service.
Subscribers ask Claude questions in plain English. Claude does the work.
- 32 callable tools spanning screener, both newsletters, personal data, and backtesting.
- Database scope: 24,000 listed companies, 200+ financial factors, 135 documented screening columns.
- Archive depth: 16 years of Quant Value (since 2010) and 3 years of Shareholder Yield Letter (since May 2023).
- Test backtest: EUR 100,000 in the Quant Value newsletter from January 2020 grew to EUR 248,830 by May 2026, with a maximum drawdown of 6.66 percent.
- Access: Best Deal subscription only. EUR 79.70 per month or EUR 779.70 per year.
What the subscriber can do
After adding the Quant Investing connector to Claude.ai (web or desktop), a subscriber asks Claude questions in plain English. Claude then calls the right tool on the Quant Investing server and formats the answer. Behind the scenes, 32 tools cover four areas:
- The Quant Investing stock screener: 24,000 listed companies, 200+ financial factors, 135 documented screening columns, with daily price refresh.
- The Quant Value newsletter archive (small-cap focus, monthly since 2010): every active pick, every closed pick, every market commentary, every original company analysis.
- The Shareholder Yield Letter archive (large-cap focus, monthly since May 2023): the same full historical depth for the large-cap strategy.
- Personal data scoped to the subscriber: watchlists, alerts, comments, saved screens, and grid templates. Each query is authenticated against a SHA-256 hashed API key bound to the subscriber's account.
Why it matters for self-directed investors
Self-directed investors have always paid the highest price in time. A subscriber screens, downloads to Excel, cross-references against a watchlist, looks up the original newsletter analysis, calculates rolling returns by hand.
The MCP service collapses this work into one chat conversation.
For our top customers we want to expand our offer at no extra cost as for them the value of the MCP is measured in hours per week rather than features per dollar.
The backtesting engine
The most distinctive part of the launch is the backtesting tool set. Three tools, sharing one engine, let a subscriber test any saved screen or either newsletter portfolio across the available history (from January 2016 to the current trading day).
Returns include dividends reinvested. Delisted stocks are priced at the last available close, which reflects how takeovers and mergers actually settle.
The benchmark for every screen is an equal-weighted basket of every stock that survives the screen's basic universe filters, capped at 2,500 stocks. Intra-period drawdown is calculated from a monthly-sampled equity curve, which is the only honest way to measure the COVID 2020 sell-off and the 2022 bear market in a 12-month-hold backtest.
Risk-adjusted metrics include Sharpe, Sortino, and Calmar ratios. Currency conversion is event-day. The system flags suspicious dividend events (typically ADR or GDR cross-currency mismatches) automatically. If you want to understand the methodology in detail, see our guide on how to back test your investment strategy.
A sample backtest of the Quant Value newsletter from 15 January 2020 to 6 May 2026, with EUR 100,000 of starting capital, the SMA cash overlay active, and dividends reinvested at event-day FX, returned EUR 248,830 (a total return of 148.83% and a compound annual growth rate of 15.56%) with a maximum drawdown of 6.66%. Across the same period the portfolio collected and reinvested EUR 43,720 of dividends across 459 separate payments. The strategy held 47.6% of ideas at a profit and 52.4% at a loss, with a win-to-loss return ratio of 4.25.
The numbers are reproducible. A subscriber asking the same question in their own account will get the same answer.
Already a Best Deal subscriber? Connect Claude in five minutes
If you already have the Best Deal subscription, the MCP connection is included. Generate an API key on your account page and add Quant Investing as a custom connector in Claude.ai.
See the step-by-step setup guide
Takes about five minutes from start to your first question.
Why only one subscription tier
Access is limited to the Best Deal subscription, which combines the screener, the Quant Value newsletter, and the Shareholder Yield Letter (EUR 79.70 per month or EUR 779.70 per year). This is a deliberate choice, not a temporary restriction.
The MCP only produces useful answers when the screener data, the 16-year newsletter archive, and the subscriber's own portfolio context are all available in one query. A screener-only subscriber would get live numbers without the editorial context that explains them. A newsletter-only subscriber would get the editorial without the live data. The bundle is the only coherent product.
Tim du Toit, founder and head analyst of Quant Investing, says:
"For 16 years the work was: screen, read, decide, hold, sell. The MCP does not change the work. It removes the friction between the steps. A subscriber asks one question in plain English and Claude returns an answer that draws on the screener, on every newsletter issue I have ever written, and on the subscriber's own portfolio. It is the first time the database has been able to answer questions in the language investors actually use."
About the strategy archive
The Quant Value newsletter has run continuously since 2010, with a 15-year track record that subscribers can verify against the backtest engine themselves. The Shareholder Yield Letter has run continuously since May 2023. The combined archive covers the European sovereign debt crisis of 2011 and 2012, the August 2015 China sell-off, the 2018 fourth-quarter drawdown, the COVID shock of 2020, the 2022 bear market across both equities and bonds, and the rate-cycle volatility of 2023 to 2025.
Every original company analysis from this period has been ingested as searchable content. A subscriber can ask Claude what the case for a 2018 pick looked like at the time, then compare that case to the company's current financials in one continuous chat. Strategy pages such as the QI Value investment strategy are also fully queryable: ask Claude to run the strategy on today's universe, then compare against the published track record.
Technical detail
The MCP server runs as a separate FastMCP instance behind a Cloudflare tunnel. Authentication uses SHA-256 hashed API keys generated from the subscriber's account page. The daily quota is 500 tool calls per key, with backtest calls counted at 5 units each.
The screener data lives in the same database that powers the live website. The newsletter content has been ingested from the source PDFs and is linked back to the screener universe by security identifier. External datasources provide foreign-exchange rates (1.96 million daily rates across 360 currency pairs since 1999) and corporate cash dividend events (827,000 events across 30,000 securities). Provider names are not exposed in any subscriber-visible output.
Frequently asked questions
What did Quant Investing launch?
An MCP server that lets Best Deal subscribers connect Claude AI directly to the Quant Investing stock screener, the Quant Value newsletter archive, the Shareholder Yield Letter archive, the subscriber's own watchlists, and a backtesting engine. 32 tools, accessible from one Claude chat.
What is an MCP server?
MCP stands for Model Context Protocol. It is an open standard published by Anthropic in November 2024. An MCP server lets a large language model (such as Claude) call specific, structured tools on a remote service. The model decides which tool to call, the server returns data, and the model formats the answer for the user.
Which subscription tier includes the MCP?
Only the Best Deal subscription, which bundles the Quant Investing screener, the Quant Value newsletter, and the Shareholder Yield Letter. EUR 79.70 per month or EUR 779.70 per year. Other subscriptions do not include MCP access.
Why is access limited to one tier?
The MCP only produces useful answers when the live screener, the 16-year Quant Value archive, the 3-year Shareholder Yield Letter archive, and the subscriber's own watchlists are all available in one query. Strip out any one of those and the conversation collapses. The bundle is the only coherent product.
What can subscribers ask?
Any question the data can answer. Examples: "Show me the top 30 European stocks by F-score above 7 with ROIC above 15 percent", "Backtest the Quant Value newsletter from 2018 in EUR and tell me the maximum drawdown", "Pull the original analysis for my 2019 Celestica pick, has the thesis aged well?", "Which active Shareholder Yield picks overlap with my Core Compounders watchlist?"
What was the backtest result quoted in the article?
A test run of the Quant Value newsletter from 15 January 2020 to 6 May 2026, with EUR 100,000 of starting capital, the 200-day SMA cash overlay active, and dividends reinvested at event-day FX rates, returned EUR 248,830 (a total return of 148.83 percent, a compound annual growth rate of 15.56 percent), with a maximum drawdown of 6.66 percent. The portfolio collected EUR 43,720 of dividends across 459 events. Hit rate 47.6 percent, win-to-loss ratio 4.25. The numbers are reproducible: a subscriber asking the same question gets the same answer.
How is this different from Stockopedia, Simply Wall Street, or Stock Rover?
Two differences. First, none of those services currently expose an MCP server to Claude or any other AI model. Second, none of them combine a 16-year proprietary newsletter archive with live screener access in one query. The Quant Investing combination of live data, editorial archive, and a working 10-year backtesting engine is unique in the market today.
Does the backtest engine benchmark against the S&P 500 or MSCI World?
No. The benchmark is an equal-weighted basket of every stock that survives the screen's basic universe filters, capped at 2,500 stocks. This is an investable universe baseline, not an index benchmark. It tells the subscriber whether the screen beats the universe it picks from.
Can I try it without subscribing?
No free trial of the MCP itself. The Best Deal subscription carries a full 30-day money-back guarantee, no questions asked. The 30-day free demo of the screener (separate product) stays as a stand alone product but does not include MCP access.
How do I sign up?
Subscribe to the Full Best Deal plan on the pricing page, then follow the step-by-step setup guide in the news section. Existing Best Deal subscribers can skip the first step and go straight to setup.
Is my data private?
Yes. Each API key is bound to one subscriber account. Personal data tools (watchlists, alerts, comments) are scoped automatically to the calling user. Keys are stored server-side only as SHA-256 hashes. The raw key never leaves the subscriber's browser.
When did this launch?
May 2026. The server has been validated against the our own screen and other newsletter portfolios with a live cache-validation test suite (six tests, all passing). The first cohort of Best Deal subscribers is being onboarded now.
Get the screener, both newsletters, and the AI connector in one bundle
The MCP only works because the live screener, 16 years of Quant Value picks, and three years of Shareholder Yield Letter analyses sit in the same database. The Best Deal subscription is the only place all three meet.
Subscribe to Best Deal and connect Claude today
100% money-back guarantee within 30 days. No questions asked.
About Quant Investing
Quant Investing is an investment research and screening service founded by Tim du Toit. The company operates one of Europe's most comprehensive stock screeners (24,000 companies, 200+ factors) and publishes two monthly investment newsletters: the Quant Value newsletter for small-cap investors (running since 2010) and the Shareholder Yield Letter for large-cap investors (running since May 2023).
Both newsletters serve self-directed investors investing their own capital. Quant Investing is owned and operated independently. The business does not accept paid promotions, commissions, or kickbacks from any company that appears in the screener or the newsletters.
Looking for more product updates? Browse the Quant Investing news section.
