1 The Story
The editor who made Dow teachable
A British-born financial journalist, Hamilton edited The Wall Street Journal from 1908 to 1929, working in the tradition of Charles Dow. In 1922 he published The Stock Market Barometer, the first comprehensive book explaining Dow's ideas.1
It was Hamilton who popularized the analogy of the primary, secondary, and minor trends as the tide, the waves, and the ripples of the ocean — an image still used to teach Dow Theory today.12
2 The Big Idea
The market is a barometer of business
The averages don't just track the economy — they anticipate it.
Hamilton argued that the market prices in conditions before they're obvious, so reading the averages is like reading a barometer. His gift was turning Dow's instinctive feel for the market into something a reader could actually learn and apply.2
3 The Method
Dow's ideas, made into a method
Tide, waves, ripples
The three trends: the primary tide (months to years), the secondary waves (counter-moves within it), and the minor ripples (daily noise).
The averages as a barometer
Read the market as a forecast of business, not just a record of it — it tends to turn before the news does.
Confirmation
Hamilton applied Dow's rule that the averages must confirm each other; a move in one not matched by the other is suspect.
Weight of evidence
Judgment over mechanical rules — change your view only when the market itself changes.
4 Try It Today
Test the idea for yourself
A no-risk exercise
On a long-term index chart, identify the primary 'tide' (the multi-year direction), then a secondary 'wave' (a multi-week counter-move within it), then the daily 'ripples.' Most trading mistakes come from confusing a wave for a change in the tide — practice keeping the three straight.
5 The Books & Their Big Ideas
What they wrote — and what to take from it
6 Watch & Read
Go deeper
§ Sources
- "William Peter Hamilton," Wikipedia — en.wikipedia.org/wiki/William_Peter_Hamilton
- "Dow theory," Wikipedia — en.wikipedia.org/wiki/Dow_theory