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Market history, written for people.

What happened last time
a stock looked like this?

Pick a name. We find similar market states in history and show the range of what followed. Then we write one note a day on the stock people are already arguing about, and we score it when the window closes. Not a forecast. Not a buy or sell.

Free. No account. Agents can use the same memory.

01

Ask about a stock

Start with a ticker and a completed trading day, in the browser or through an agent.

02

See similar history

Read how many comparable days we found, and the range of what followed.

03

Notice the limits

A similar-looking day can still have different news. Missing evidence stays missing.

Start here

Three ways in.

Today's note

One trending name, the range from similar history, and a score at the close.

Read the notes

Look up a stock

Choose any ticker. See comparable days and the range of what followed.

Search a stock

How to read a result

What the low, middle, and high numbers mean, and when history is a poor guide.

How it works
A worked example

IONQ at noon: what similar-looking charts left out.

We found historical matches, then looked at the hour before each one. The clock and the earlier move changed the comparison.

Read the case
IONQ compared with similar-looking historical charts before the cutoff
The research behind the memory

What have we learned?

Read the studies

We test what makes a useful comparison, where similar-looking history breaks down, and what the evidence can support. Failed tests stay in the record.

MemoryStudy 100

Similar charts narrow the spread among analog outcomes

Closer historical matches had less spread among their later outcomes. This does not establish a narrower forecast band for the stock being examined or predict its direction. Study 101 tested the weighting follow-up.

Pass

Each result belongs to its own question, sample, and date. A pass does not bless every other page on this site.

If you build with AI

Give your agent the same history.

Connect through MCP or REST. Each public tool answers a research question with dates, sample sizes, and limits your agent can keep next to its answer.

https://chartlibrary.io/mcp

Agent tools and setup

An example question

What does AAPL’s latest completed session resemble in history?
market_state(symbol="AAPL")

What the tool returns

  • Current and previous market-state context
  • Historical comparisons and the range of outcomes that followed
  • Earlier comparable state transitions across stocks
  • Session dates, sample sizes, warnings and provenance

These ranges describe the historical sample. They are not automatically calibrated forecasts.

Illustrative call. This example does not run a live request.

An independent research project

Look up the history.
Read the note. Keep the score.

Chart Library is the public market-history tool. Alphaforge writes the daily notes using that history. Both are free. Neither is a recommendation.