On This Page
Key Takeaways
- TICK nets the stocks whose last trade was an uptick against those whose last trade was a downtick: the example’s +1,270 means 1,270 more stocks are ticking up than down right now.
- TRIN, the Arms Index, divides the advancing-to-declining issue ratio by the advancing-to-declining volume ratio, which makes it equal to average volume per declining issue divided by average volume per advancing issue.
- TRIN reads inversely and compares volume per issue rather than total volume: below 1.00 the average advancing issue carries more shares than the average decliner, and above 1.00 the average decliner carries more.
- TICK is an instant reading, so watch how long a reading holds. TRIN measures the session against the prior close, and it jumps when a heavily traded stock crosses that line.
- TRIN 1 means equal average share volume per advancing and declining issue. It counts shares, so low-priced stocks weigh more than their dollar turnover.
- Choose the exchange or index universe that matches the market setup being analyzed.
What are the TICK and TRIN indicators?
The TICK and TRIN indicators are market internals that measure participation across a universe of stocks, such as NYSE-listed issues. TICK counts upward tick states minus downward tick states. TRIN, or the Arms Index, compares average volume per declining issue with average volume per advancing issue, so a reading below 1.00 means the average advancer traded more shares than the average decliner.
Pick the exchange or index universe and match the observation times. TICK reads recent tick direction; TRIN reads price against the prior close. Traders use both to confirm a price setup on the index: internals that agree with a breakout back it, and internals that fight it warn that few stocks are joining in. The trigger, stop and size still come from the chart.
How is TICK calculated?
In this example, a higher trade creates an up state, a lower trade creates a down state and an equal-price trade retains the last nonzero direction. An issue with no established direction remains unclassified.
The example reading has 2,050 up states, 780 down states and 170 unclassified issues. TICK = 2,050 − 780 = +1,270.
An issue switching from down to up moves the count by +2. Raw TICK is an instant reading; a running sum of sampled TICK is a separate series with its own sampling rule.
Before you compare two TICK charts, match each feed’s tick rule, including how it counts trades at an unchanged price, and its opening start and reset.
Formula
TRIN = (advancing issues / declining issues) / (advancing volume / declining volume) = (advancing issues × declining volume) / (declining issues × advancing volume); TICK = issues whose last price change was an uptick − issues whose last price change was a downtick- Use issue counts and volumes from the same universe and observation time; all four inputs must be positive.
- TRIN is algebraically identical to average volume per declining issue divided by average volume per advancing issue.
- Because that comparison is per issue, TRIN can print above 1.00 in a session where total advancing volume still exceeds total declining volume.
- TRIN below 1.00 means more volume per advancing issue than per declining issue, and above 1.00 means the reverse.
- A trade at an unchanged price keeps the stock’s last nonzero direction, and a stock with no direction yet stays out of the up and down counts.
- Each stock counts once, so TICK can never exceed the universe: 3,000 either way for the example’s 3,000 issues. A running total of TICK readings is a separate indicator.
Worked Example
A 3,000-issue example has 1,800 advancing, 1,000 declining and 200 unchanged versus the prior close. Their advancing and declining volume totals are 720M and 480M shares. The separate tick states are 2,050 up, 780 down and 170 unclassified.
- Advance-decline issue ratio: 1,800 / 1,000 = 1.80
- Advancing-declining volume ratio: 720,000,000 / 480,000,000 = 1.50
- TRIN = 1.80 / 1.50 = 1.20
- Average volume per advancer: 720,000,000 / 1,800 = 400,000 shares; per decliner: 480,000,000 / 1,000 = 480,000 shares
- Cross-check: 480,000 / 400,000 = 1.20, the same TRIN
- TICK = 2,050 upticks − 780 downticks = +1,270
TICK is +1,270. TRIN is 1.20 because the average declining issue has 480,000 shares versus 400,000 for the average advancing issue. Total advancing volume is still larger at 720M versus 480M. Read them together: TICK has buyers pressing this instant, and TRIN puts the session’s heavier volume per stock in the decliners.
How is TRIN calculated?
Let A and D be current advancing and declining issue counts, and UV and DV their assigned volumes. With positive inputs, TRIN = (A / D) / (UV / DV) = (DV / D) / (UV / A).
The example has A = 1,800, D = 1,000, UV = 720M shares and DV = 480M shares. The issue ratio is 1.80 and the volume ratio 1.50, giving TRIN 1.20.
Average volume is 400,000 shares per advancing issue and 480,000 per declining issue. Their ratio is also 1.20. Advancing issues still account for more total shares.
Why TICK and the daily advance-decline count differ
A stock below its prior close can have an upward latest tick, and a stock above its prior close can have a downward one. So a positive TICK can print on a day when decliners lead: TICK reads this instant, and the advancing-minus-declining count reads the session.
The complete example uses 3,000 issues: 1,800 advancing, 1,000 declining and 200 unchanged on the session. Its tick states add to the same total: 2,050 up, 780 down and 170 unclassified.
Why TRIN can change sharply
A provider can group each stock’s session volume according to whether it currently trades above or below its prior close. When a stock crosses that reference, its accumulated volume changes groups.
In a constructed continuation of the example, one advancing stock with 600M accumulated shares crosses below its prior close on a one-share trade. The counts move to 1,799 advancing and 1,001 declining, and the stock’s volume moves with it: advancing volume drops to 120M, and declining volume jumps to 1,080,000,001, the 480M already there plus the stock’s 600M and the one-share trade. TRIN jumps from 1.20 to 16.17.
One stock did that. Before you act on a sharp TRIN move, check whether the issue counts moved with it or a single heavy name switched sides.
Averaging TRIN readings and share volume
The arithmetic average of TRIN readings 0.50 and 2.00 is 1.25, which tilts bearish; their geometric average is 1.00, which treats half and double as equal and opposite. Pooling the four raw inputs before calculating gives a third answer, so pick one method and keep it.
Share volume counts shares, not dollars. For equal dollar turnover, a lower share price produces more shares, so low-priced stocks weigh more in TRIN.
Limitations of TICK and TRIN
- Compare readings only within one feed and universe. NYSE, Nasdaq and index variants, tick rules, opening initialization and volume grouping all change the numbers, so set your levels on the feed you trade.
- Judge TICK by how long it holds. It reads the latest tick direction this instant, swings between samples, and can stay positive on a day when decliners lead.
- Read TRIN as volume per issue. The example’s 1.20 leans bearish while advancing issues carry 720M shares against 480M.
- Check a sharp TRIN jump for a single heavy stock first. One name crossing its prior close moves its whole accumulated volume between groups, as in the constructed 16.17 reading.
- Take the trigger and stop from the price chart, and use TICK and TRIN to confirm the participation behind it.
Bottom line
TICK and TRIN describe market participation from two angles: the balance of latest tick directions and the volume carried by the average advancing and declining issue. Read them on one fixed universe and feed, check issue counts and volume groups before trusting a sharp move, and use them to confirm the participation behind a defined price setup.
Clear answers
Frequently Asked Questions
Sources and Further Reading
How entries are sourced, calculated and updated: editorial methodology.