The Echo Index

How much is the market rhyming bullish?

Every week we match the liquid stock and crypto universe against decades of chart history and count where the closest look-alikes went next. This is that count — precedent, not prediction.

Week of 2026-08-17 · 420 liquid charts measured · ≥5 precedents each

67%precedents leaned bullish

19%leaned bearish

13%split

This week's spotlight: BCH’s last 90 sessions most resemble ETCUSD, 2018-11-06 → 2019-02-03. Across its 25 closest precedents: 68% resolved up, 28% down, median move +55.25%.

Where the archive disagrees: CC splits history hardest this week — 48% of its 25 precedents resolved up, 48% down. When history can’t agree, that’s a finding too.

What this number is

Chart Echo indexes hundreds of millions of historical chart windows. Each week we take the last 90 daily closes of every liquid stock and crypto chart in our universe, find each one’s closest historical look-alikes, and read what those precedents actually did next. The Echo Index is the share of charts whose precedents leaned bullish, bearish, or came back split.

What it is not

A forecast. Precedent is a base rate, not a promise — regimes change, and the next case can always be the exception. We publish the split and the disagreements precisely so this stays honest. Method and limitations are documented in Methodology & limits.

Citing the Echo Index? Link to this page for the current reading — it updates here every week at the same URL. To cite one specific week, link its dated permalink in the archive below; those pages never change after publication.

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Every published reading

The Echo Index is published weekly and each reading keeps its own permanent page. Nothing here is revised after the fact — the series is the record.