{"concept":{"id":"https://www.thetrading.tools/concepts/breadth-thrust#term","slug":"breadth-thrust","canonicalUrl":"https://www.thetrading.tools/concepts/breadth-thrust","name":"Breadth Thrust","alternateNames":["breadth momentum thrust","participation thrust"],"category":"Market breadth","kind":"Signal family","shortDefinition":"A rapid, unusually broad expansion in market participation after weakness or a washout.","definition":"A breadth thrust is a family of signals that identify a fast expansion in the number or volume of advancing securities, usually after participation was weak or washed out. The shared idea is speed plus breadth; the exact universe, input, smoothing rule, thresholds and time window depend on the named implementation.","plainIntro":["\"Breadth\" is a simple idea: instead of asking whether the market index went up, ask how many individual stocks went up. An index can rise because a handful of giant companies rose while most stocks fell — breadth tells you whether the crowd actually came along.","A breadth thrust is the moment that crowd behavior flips violently: the market goes from most stocks falling to nearly everything rising, within days. Think of a stadium wave — not one section cheering while the rest sit, but the whole stadium on its feet almost at once.","Analysts care because that kind of stampede has historically happened near the start of big recoveries, not in the middle of ordinary weeks. But \"breadth thrust\" is a family name, not one rule — different analysts define the stampede with different measurements, which is why this page exists."],"whyItMatters":["A price index can rise because a handful of large constituents advance. A breadth thrust asks whether buying has spread quickly across many securities or a very large share of volume.","The speed requirement separates a sudden regime change from a slow repair. Many implementations were designed to flag the transition from liquidation or pessimism to unusually broad demand.","The label alone is incomplete. A Zweig Breadth Thrust, a 90% up-volume day and other breakaway-momentum rules use different inputs and horizons, so their event lists and evidence cannot be pooled without restating the rule."],"formulas":[{"label":"Signal-family template","expression":"weak breadth → broad surge within a fixed window","explanation":"Every implementation must state its universe, participation input, smoothing method, low and high thresholds, and maximum elapsed sessions."},{"label":"One named implementation","expression":"10-day EMA of A / (A + D): below 0.400 → above 0.615 within 10 sessions","explanation":"This is the Zweig rule used by our live gauge. It is one member of the breadth-thrust family; the generic definition of every thrust lives on the Breadth Thrust page."}],"example":{"title":"Why the rule must be named","setup":"Imagine 91% of exchange volume flows into advancing stocks today, while the 10-day EMA of advancing issues rises only from 0.38 to 0.49.","steps":["The session qualifies as a 90% up-volume day because the volume threshold was crossed.","The Zweig gauge is armed because its EMA was below 0.40, but it has not reached 0.615.","Follow-through over the remaining window could complete a Zweig thrust; today's volume event cannot complete it by itself."],"result":"One breadth-thrust variant fired; another did not.","interpretation":"“Breadth thrust” should be followed by the named rule or a complete formula. Similar intuition does not make two event definitions interchangeable."},"caveats":["There is no single universal breadth-thrust formula. Publishing a signal without its universe, input, thresholds and window makes the observation non-reproducible.","Issue-count and volume-based measures answer different questions. A market can have broad participation by count without 90% of volume moving the same way, or vice versa.","Rare-event forward returns come from small samples and overlapping market regimes. Report the full event count and ungraded recent events rather than only a hit rate.","The absence of a thrust is not a bearish signal. Markets can recover gradually or continue rising without first producing the washout required to arm a particular rule."],"faq":[{"q":"Is there one official breadth-thrust definition?","a":"No. Breadth thrust is a signal family. Named implementations differ by exchange or stock universe, issue count versus volume, smoothing, thresholds and window; a reproducible claim must state all five."},{"q":"Is a 90% up day the same as a breadth thrust?","a":"It is a related volume-based thrust event, but not the same as a multi-session issue-count rule such as Zweig. One extreme session can occur without the sustained EMA move required by Zweig."},{"q":"Does no breadth thrust mean a rally is weak?","a":"No. Most days and many durable advances do not produce rare named thrusts. The absence of a signal says its setup and speed conditions were not met, not that future returns must be poor."}],"sources":[{"name":"What Is a Breadth Thrust and What Are the Risks?","publisher":"CMT Association","href":"https://cmtassociation.org/technically_speaking/technically-speaking-november-2022/","note":"Professional reference for the breadth-thrust concept and its technical-analysis lineage.","primary":false},{"name":"Winning on Wall Street","publisher":"Martin Zweig / Warner Books","note":"Original published source for the named Zweig Breadth Thrust rule.","primary":true},{"name":"Market breadth data methodology","publisher":"The Trading Tools","href":"/methodology","note":"Universe filters, timestamps and reproducibility standards used by our live observations.","primary":true}],"resources":[{"type":"tool","name":"Market Breadth","href":"/market-breadth","relation":"Shows the daily advance/decline participation inputs before a named thrust rule is applied."},{"type":"manual","name":"The Market Breadth Manual","href":"/manuals/market-breadth","relation":"Places thrusts inside a broader framework of participation, divergence and trend confirmation."},{"type":"tool","name":"Zweig Breadth Thrust gauge","href":"/zweig-breadth-thrust","relation":"Implements one named issue-count rule with a daily EMA, armed state and event catalog."},{"type":"signal","name":"90% Up/Down Days","href":"/ninety-percent-days","relation":"A related single-session volume measure; it uses up-volume, while the Zweig EMA uses advancing issues."}],"relationships":[{"relation":"broaderThan","conceptId":"https://www.thetrading.tools/concepts/zweig-breadth-thrust#term","slug":"zweig-breadth-thrust","name":"Zweig Breadth Thrust","url":"https://www.thetrading.tools/concepts/zweig-breadth-thrust","description":"The Zweig rule is one named, path-dependent implementation inside the broader breadth-thrust family."},{"relation":"relatedTo","conceptId":"https://www.thetrading.tools/concepts/drawdown#term","slug":"drawdown","name":"Drawdown","url":"https://www.thetrading.tools/concepts/drawdown","description":"Drawdown measures the price decline from peak within which breadth washouts — the arming condition for thrust rules — typically develop."},{"relation":"relatedTo","conceptId":"https://www.thetrading.tools/concepts/unusual-volume#term","slug":"unusual-volume","name":"Unusual Volume","url":"https://www.thetrading.tools/concepts/unusual-volume","description":"Unusual volume applies the same participation-intensity idea to a single security against its own baseline, where a breadth thrust aggregates participation across the whole market at once."}],"dataDependencies":["https://www.thetrading.tools/data/zweig_breadth_thrust/zweig_breadth_thrust.json","https://www.thetrading.tools/data/ninety_percent_days/ninety_percent_days.json"],"cadence":"trading-day","publishedAt":"2026-08-10","reviewedAt":"2026-08-11","modifiedAt":"2026-08-11"},"currentObservation":{"@type":"Observation","id":"https://www.thetrading.tools/concepts/breadth-thrust/observations/2026-08-21","conceptId":"https://www.thetrading.tools/concepts/breadth-thrust#term","asOf":"2026-08-21","label":"Observed implementation · Zweig Breadth Thrust","headline":"Not armed — 10-day EMA 0.499","detail":"The named rule cannot complete until its EMA first falls below 0.400. The last completed event on our disclosed universe was 2019-01-08.","active":false,"tone":"neutral","metrics":[{"label":"10-day EMA","value":"0.499"},{"label":"State","value":"Neutral"},{"label":"Completed events","value":"6"},{"label":"Last event","value":"2019-01-08"},{"label":"With 90% up-volume day","value":"5 of 6"}],"methodology":"10-day EMA of Advances / (Advances + Declines), below 0.400 then above 0.615 within 10 sessions, on our disclosed common-stock universe.","source":"/data/zweig_breadth_thrust/zweig_breadth_thrust.json"},"separationNote":"The concept is the durable definition. currentObservation is a dated measurement produced by the named implementation and may be null when its source is unavailable."}