How to backtest with Claude on real stock data

// CLAUDE CODE (TERMINAL)

claude mcp add --transport http quantgpt https://terminal.quantgpt.co/mcp

1. Run the line above, then start claude.
2. Type /mcp, pick quantgpt and choose Authenticate. Your browser opens QuantGPT's own sign-in; if it opens the wrong browser, Claude Code prints the link, so you can paste it into the one you are signed in on.
3. Sign in and press CONNECT. Back in Claude Code, quantgpt shows as connected.
4. Ask it to call describe_capabilities. It starts with the core desk; ask it to call available_categories when a task needs the equity, portfolio, macro or alt-market tools, and it switches them on for your account.

The connection appears as a key on your account page, where you can revoke it.

For scripts and servers, where nobody is there to sign in, use a key instead: on your account page, under Keys for your AI, type a label and press Issue key, and copy the qg_sk_... value at once (only its hash is stored). Then:

claude mcp add --transport http quantgpt https://terminal.quantgpt.co/mcp --header "Authorization: Bearer qg_sk_YOUR_KEY"

// CLAUDE DESKTOP AND CLAUDE.AI

1. Open Customize, then Connectors.
2. Click + and choose Add custom connector. On a Team or Enterprise plan an Owner may need to add it first.
3. Name it QuantGPT. URL: https://terminal.quantgpt.co/mcp. Leave the OAuth client fields empty and click Add.
4. Press Connect. Claude opens QuantGPT's sign-in page: sign in and approve. The connection shows on your account page as a key labelled connector: Claude, and you can revoke it there.
5. Start a new conversation and ask Claude to call describe_capabilities.

// PROVE IT WORKED

"Using QuantGPT: call the guide tool and walk me up THE RAMP
from wherever I am. Then run a classic momentum study, 1990 start,
and state plainly what failed."

Back in the terminal, the AI light in the nav turns green after the first call. That is RAMP 05 and 06 done.

// WAYS TO GIVE CLAUDE STOCK DATA, COMPARED

If you want Claude to run backtests on real history without building anything, use the connector, or the key for scripts. If you only want Claude to walk you through the steps, use the paste-pack.

// WHAT A BACKTEST GIVES BACK

When Claude runs a backtest through QuantGPT, the answer comes back with the numbers that produced it:

• Growth a year, the worst drop and the Sharpe ratio (how much return for the bumps along the way), each beside the S&P 500 with dividends reinvested.
• A check on years it was not tested on. The history is split at a year, 2015 unless you pick another, and the years after it are scored on their own.
• Decade by decade, so one great stretch cannot hide a bad one.
• Results after trading costs at four cost levels, and the exact number of trades. The headline numbers are gross of costs.
• The finding. DATA VALIDATED means it beat the S&P 500 on growth and on Sharpe and held up in the later years; TRADE-OFF means it won on one of the two; NO EDGE means it won on neither.

Here is a real one, run on October 27, 2026: the 200-day rule on SPY, the S&P 500 fund. At each month end it holds SPY while the price is above its average of the last 200 trading days, and cash while it is below. From January 1998 to September 2026, against the S&P 500 with dividends, gross of costs:

• Growth a year8.97% against 9.38% for the S&P 500
• Worst drop23.0% against 50.9%
• Sharpe ratio0.88 against 0.66
• From 2015 on8.91% a year against 14.17%, Sharpe 0.84 against 0.97
• FindingTRADE-OFF

TRADE-OFF here means the rule gave up 0.41 points of growth a year for less than half the worst drop and a higher Sharpe ratio. Claude reads you all of it, and can then change one setting, such as the start year or the benchmark, and run it again in the same conversation.

// WHY THE DATA MATTERS

A backtest on only the companies that still trade today looks better than the market really was, because the ones that failed are missing. In QuantGPT's market-wide backtests, companies that later delisted are included from 1998 on: 12,521 of the 12,841 with prices, or 98%. Before 1998 the data holds only companies that survived. Company numbers such as earnings are used from the day they were filed, so a backtest only sees what was known at the time.

// OTHER ASSISTANTS

The same server connects to other AI apps too. Step-by-step guides: ChatGPT · Gemini · Cursor.

// LIMITS AND BOUNDARIES

AI calls are counted per account, across all your keys and connections: 500 a day on QuantGPT and 1,500 a day on QuantGPT Pro, the 3-day trial included. No tool your AI can call places, modifies, or cancels an order; a few save things to your own QuantGPT account, such as a saved study or an alert. Rotate keys from the account page any time (1 active key on Free, 3 on QuantGPT, 5 on QuantGPT Pro).

// QUESTIONS

Backtests are hypothetical and gross of trading costs unless stated; past results do not predict future ones. Setup steps checked October 27, 2026; Claude's menus can change.