1 · Observe
Start with reported trade
Market value, exporter value, supplier shares, and route history describe what was reported. These values are not generated forecasts.
Trade anomaly guide
What does a trade
anomaly mean?
An anomaly is an unusual movement in a reported exporter-to-importer-product trade series. It is a research prompt, not a cause, forecast, buyer signal, or guarantee.
The basic idea
An anomaly is unusual movement, not an explanation.
Each observation describes one year, exporter, importer, and product. A signal is shown when the reported movement is unusual against the comparison used by the published trade statistics.
2 · Compare
Put the observation in context
Growth, momentum, volatility, concentration, and historical movement help show whether the observation differs from its comparison baseline.
3 · Investigate
Ask what may have changed
Check product specifications, buyers, suppliers, tariffs, standards, logistics, pricing, and current news before assigning a cause.
Before reading the numbers
What do exporter, importer, HS6, route, and year mean?
These labels identify the subject of an anomaly page. They are not scores.
| Term | Plain-language meaning | |
|---|---|---|
| Exporter | The country from which the reported goods were shipped. | Identity |
| Importer | The country or market receiving the reported goods. | Identity |
| HS6 code | A six-digit international product classification. It identifies the product category being measured. | Identity |
| Trade route or corridor | One exporter, one importer, and one HS6 product considered together. | Identity |
| Year | The reporting year for the trade observation. The page may also show earlier years for comparison. | Identity |
| USD | United States dollars. Dollar values are reported trade values, not prices offered to a buyer. | Unit |
| Percentage points | The difference between two percentages. A change from 10% to 13% is +3 percentage points. | Unit |
The logic from start to finish
How the numbers are put together.
This is the complete reader-facing flow. A missing input remains unavailable; it is not silently changed to zero.
Step 1
Choose one route and product
Identify the exporter, importer, HS6 product, and reporting year. This prevents values from different markets or products being mixed.
Step 2
Measure the reported market
Read the buyer-market imports and the exporter’s reported value for that HS6 product and year.
Step 3
Calculate change and position
Calculate market share, year-on-year change, multi-year growth, momentum, and acceleration when the required comparison years exist.
Step 4
Compare the movement with history
Use the data source’s standardized score and direction to identify an unusual upward or downward movement.
Step 5
Add market context
Show suppliers, concentration, volatility, drawdown, tariffs, and access indicators so the movement is not read in isolation.
Step 6
State what is known and unknown
Separate reported observations from calculations and explain that the movement does not identify the cause or guarantee a commercial outcome.
What each number means
Reported values and calculated indicators stay separate.
The formulas below explain the measures used for interpretation. The threshold used to label a row as an anomaly comes from the published data source; it is not a probability and is not invented on this page.
| Measure | Calculation or meaning | Kind |
|---|---|---|
| Market imports | Reported imports into the buyer market for this HS6 product and year. | Reported |
| Exporter market share | Exporter trade value / buyer-market imports × 100. | Calculated |
| Year-on-year momentum | (Current value - previous value) / previous value × 100, when the previous value is valid. | Calculated |
| Momentum acceleration | Current year-on-year momentum - previous year-on-year momentum. This is normally read in percentage points. | Calculated |
| Three-year CAGR | (Ending value / starting value)^(1 / number of years) - 1, expressed as a percentage. | Calculated |
| Anomaly z-score | Conceptually, (observed value - comparison average) / comparison standard deviation. The data source supplies the comparison window and published value. | Calculated |
| Anomaly type | The reported direction of an anomaly, currently shown as a spike or drop when a movement is present. | Reported indicator |
| Anomaly severity | The reported strength indicator. It is not a chance of success, loss, or future growth. | Reported indicator |
Supporting values
What the surrounding market numbers mean.
Anomaly interpretation improves when the signal is read with the market, supplier, and route measures around it.
| Value | Calculation or meaning | Kind |
|---|---|---|
| Supplier count | Number of reported exporter countries supplying the buyer market. | Reported |
| Market HHI | Add the squared market share of each supplier. Higher values indicate a more concentrated supplier market. | Calculated |
| Volatility CV | Standard deviation / average of the observed route series. Higher values indicate less stable movement. | Calculated |
| Maximum drawdown | The largest percentage fall from an earlier observed peak. | Calculated |
| Share gap | Exporter share minus the strongest reported peer share, expressed in percentage points. | Calculated |
| Applied tariff | The reported tariff measure available for the route and product. It is not inferred from the anomaly. | Reported |
Use the signal carefully
What an anomaly cannot tell you.
Trade data can show an unusual observation without identifying the event that caused it.
It is not a named buyer
The page does not identify a company, purchase order, confirmed demand, or commercial contact.
It is not a forecast
A spike may reverse and a drop may recover. The signal does not predict the next year.
It is not causal evidence
Policy, supply, pricing, logistics, reporting, and product-mix changes may all affect a route. Investigate before concluding why.
It is not a probability
A z-score or severity value must not be read as a percentage chance of success, loss, or future growth.
Worked example
See the explanation on a real route.
The example keeps the product identity, reported observations, calculated indicators, and interpretation separate.
United Kingdom → Brazil · HS6 853110 · 2024
United Kingdom to Brazil trade anomaly
Product: Signalling apparatus for burglar or fire alarms and similar uses.
The route shows a reported spike, a 2.70 standardized score, 67.4% reported severity, $43.7M in buyer-market imports, +92.5% exporter momentum, and a 3.77% exporter market share. These values describe the movement; they do not explain its cause.
Frequently asked questions
Reading unusual trade movements responsibly.
Plain-language definitions for the fields used on trade anomaly pages.
What do exporter, importer, and HS6 mean?
Exporter is the shipping country, importer is the receiving market, and HS6 is the six-digit product classification used to identify what was traded.
Does an anomaly mean trade is growing?
Not necessarily. A spike or drop describes unusual movement in the source comparison. Check the reported values and direction for the route.
Is a z-score a probability?
No. It is a standardized comparison measure, not a probability or forecast.
Why might a value be unavailable?
Some calculated comparisons need a valid prior observation or stable denominator. Missing values are shown as unavailable rather than treated as zero.
What should I do next?
Use the signal to investigate the product, suppliers, market access, tariffs, logistics, pricing, and current market information.
Continue your research
Move from an unusual observation to an evidence review.
Open a route example or review the formal methodology and data-source pages.
Data source
OECD trade statistics with CEPII context
OECD (2025), Balanced international merchandise trade statistics (BIMTS) - HS2017-6D, OECD Data Explorer (accessed on 2026-09-03). OECD BIMTS is the primary trade series for this view. Supporting bilateral trade context uses CEPII BACI bilateral trade flows (202601) under Etalab 2.0 Open Licence. Yugalinks presents derived views of reported observations and calculated indicators. Data terms: OECD Terms & Conditions.