# Limits of inference

**FUT-29 · Equity Index Futures · Core**

**Lesson question:** What questions can futures not answer?

Original fictional examples; educational writing, not live market data, orders or production approval.

## By the end

- Explain the mechanism in the lesson question.
- Reproduce the worked comparison and recognize its failure case.

**Prerequisites:** FUT-01

A futures quote is a price for a particular dated contract. It is not a diagnosis of every stock, a promise about the next cash close or proof of a dealer's intent.

Good analysis extracts useful broad context without asking it to answer unrelated questions.

## Understand the mechanism

An index can rise while a constituent falls. A thin-session move can reverse. Positive basis can reflect carry. An index hedge can work while a company's earnings surprise dominates its shares.

These are limits of an inference, not defects in the instrument.

## Walk through the process

Identify every assumption added beyond the observed quote. Seek company information for business questions, signed inventory evidence for dealer claims and synchronized data for lead–lag questions.

An explicit 'not established' is more useful than an unsupported universal signal.

## Operational boundary

All figures are fictional teaching inputs, not current quotes or margin schedules. Product rules, broker requirements and usable liquidity remain separate from the model example. A planned exit and an algebraic hedge are not execution guarantees.

## A worked example

A fictional future rises 1% while one stock falls 6% after company information. With estimated Beta 1.2, the simple market component would be +1.2%, leaving −7.2 percentage points unexplained.

That arithmetic highlights the need for company research. It does not guarantee a reversal or prove the Beta estimate remains appropriate. The graph compares the different pieces.

## Graph: Limits of inference—worked comparison

**Horizontal:** Market / stock / modeled component  
**Vertical:** Return (%)

Fictional data from the written example. The chart organizes the comparison; its shape is not a forecast.

Complete numerical data are embedded in `scripts/equity-futures/FUT-29.js` and displayed as an accessible table in the HTML lesson.

## What would invalidate the reading?

Buying every stock because futures are green ignores idiosyncratic risk. Treating unexplained movement as automatic mean reversion compounds the mistake.

## Check your understanding

### Does a green index establish a bullish thesis for every constituent?

**Answer:** No.

**Why:** Broad context and company value are different questions.

### What is the critical failure to avoid?

**Answer:** Buying every stock because futures are green ignores idiosyncratic risk. Treating unexplained movement as automatic mean reversion compounds the mistake.

**Why:** Explain this risk before treating the example as a decision rule. A correct calculation does not guarantee a favorable market outcome. **Critical risk check.**

## Takeaway

Return to the question: What questions can futures not answer? State the observed facts, the assumptions and the failure condition separately.

## References and provenance

The cited references support definitions and conventions. The teaching prose, tickets and numerical scenarios are original; they are not attributed as historical market observations.

- [CME Introduction to Futures](https://www.cmegroup.com/education/courses/introduction-to-futures)

- [CME Micro E-mini overview](https://www.cmegroup.com/education/courses/micro-e-mini-futures/micro-e-mini-futures-products-overview)