# Historical Comparison

> Twin decision-support. Chains event-study (what happened around a specific event) with historical-analog-finder (what usually happens in setups like now). Useful before making a call where both name-specific event evidence and market-wide regime analog matter. Also runs analog-only mode when no ticker is supplied.

- Skill: `rgourley/historical-comparison` (Agent Skill, multi-file: 5 files)
- Install (CLI): `npx skillmds@latest add rgourley/historical-comparison`
- Raw SKILL.md: https://api.skillmd.com/api/skills/rgourley/historical-comparison/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: rgourley (https://skillmd.com/u/rgourley)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/rgourley/historical-comparison

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# historical-comparison

Twin comparison: event-study on the ticker + historical-analog-finder
on the market. The idea: don't rely on one anchor when you can use
both.

## When to invoke

- Analyst wants both "here's what happened around this specific event"
  and "here's what usually happens in setups like this"
- Before a directional call where both name-specific and market
  context matter
- Analog-only mode (no ticker): just the market regime forward
  distribution

## Modes

- **Event mode**: pass ticker + event_class + optional event_date /
  period. Both event and analog run.
- **Analog-only**: pass `include_event=False`. Only the market
  analog runs.

## What you get back

**Layer 1 JSON** matching [`output-schema.json`](./output-schema.json).
Headline distills the T+5 CAR + prior percentile from event-study
plus the median/IQR/hit-rate at 90d from the analog.

**Layer 2 rendered brief**. See
[`references/rendering.md`](./references/rendering.md).