Conditional co-movement · synchronized clocks · causal restraint
6N Correlations: A Conditional Co-Movement Test
A 20-session window can show 6N and another market moving together while a 120-session window shows the opposite sign. Neither number is automatically wrong. They answer different questions, and neither establishes why the assets moved.
- Measure
- Returns
- Windows
- Predeclared
- Causality
- Not assumed
- Original findings
- None
Question before coefficient
Specify the Relationship You Mean to Test
“6N is correlated with risk assets” is too broad to test. A registered claim names the second series, return horizon, observation clock, contract-roll policy, sample, conditioning state, estimator, uncertainty method and decision use.
Protocol statement—not a result
Estimate whether synchronized 6N and candidate-market returns exhibit a stable conditional relationship after broad-dollar and rate controls, then test whether that relationship survives later chronological data and executable costs.
- Fact
- 6N is a dated NZD/USD future
- Hypothesis
- Co-movement may vary by state
- Allowed answer
- Unstable or unusable
CME Rulebook Chapter 258 defines the deliverable NZD/USD futures contract. A research series must retain delivery-month identity.
A positive estimate may be consistent with a shared growth or dollar shock. It does not identify that shock without additional evidence.
A relationship becomes usable only if a frozen decision rule improves a relevant benchmark in later data after costs. This page reports no such test.
Comparable transformations
Correlate Returns, Not Convenient Price Levels
Two trending price levels can create a persuasive coefficient even when their changes are unrelated. Convert prices with a declared transformation, use the same horizon, and avoid overlapping observations unless the uncertainty calculation accounts for dependence.
rt = ln(Pt / Pt−1)→ρt,w = corr(r6N, rX) over window w| Candidate | Series construction | Main ambiguity |
|---|---|---|
| 6A futures | Dated futures returns with the same roll and clock policy as 6N | Shared USD quotation versus distinct domestic drivers |
| Equity futures | Returns from a declared CME expiry and close or synchronized intraday mark | Which market session contained the information? |
| U.S. rates | Yield changes, not yield levels; maturity fixed in advance | Level, slope and policy expectations can move differently |
| Commodities | Return on a named futures contract or official index | Export narrative may be indirect and lagged |
| Broad USD | Change in an external broad-dollar measure | Contemporaneous control is not a tradable advance signal |
RBNZ’s B1 exchange-rate and Trade Weighted Index series supplies official daily NZD reference data and a 17-currency TWI. It is a separate data product from executable CME 6N quotes.
The clock is part of the variable
Synchronize Information Windows Before Estimating Anything
A New Zealand release, a U.S. equity close and a CME trade-date boundary do not share one civil-day clock. Same-date joins can pair a 6N return with information that arrived after it.
Preserve source time
Retain exchange timestamps, source timezone, UTC offset and trade date.
Define the window
Use close-to-close, fixed UTC bars or event windows chosen before outcomes.
Resolve calendars
Version holidays, daylight-saving changes, missing observations and early closes.
Join causally
Use only values whose publication or market timestamp precedes the endpoint.
When one market is closed or an input is stale, mark the pair ineligible or apply a predeclared carry rule. Never treat a repeated value as a fresh observation without disclosure.
Candidate causes, not labels
Keep Mechanisms Separate From Measured Co-Movement
A mechanism suggests what to condition on and what could falsify the story. It does not authorize a direction forecast. Several channels can act at once, oppose one another, or disappear when policy and positioning change.
Broad-dollar channel
A common USD move can affect both 6N and another USD-quoted market. Test a broad-dollar control and avoid using an index with circular composition as causal proof.
Relative-rate channel
Changes in New Zealand and U.S. rate expectations can alter carry and valuation. Use dated curve changes, not only current policy-rate levels.
Growth and risk channel
A shared growth repricing can move equities, commodities and NZD together. That relationship may fail in a domestically driven shock.
Liquidity and positioning
Deleveraging, roll migration or thin books can create transient co-movement that does not represent a durable macro link.
One coefficient is not a regime
Publish Rolling Estimates With Their Uncertainty
Choose a primary window for the decision horizon and a limited sensitivity set. Report the number of paired observations, missing-data policy, confidence interval or block-bootstrap distribution, and every candidate relationship examined.
Primary
Pearson
Measures linear co-movement and is sensitive to outliers. Use only with a documented return and cleaning policy.
Rank check
Spearman
Tests monotonic rank association. It is a robustness check, not an automatic replacement for the primary estimator.
Conditional
Partial model
Residualize against predeclared controls using training data only. Interpret model dependence explicitly.
Timing
Lead–lag grid
Use a narrow preregistered lag set and correct for searching. A best lag selected after inspection is exploratory.
- Keep signs and magnitudes. Do not reduce estimates to “correlated” or “not correlated.”
- Show window endpoints. A rolling value must be traceable to the observations it used.
- Account for dependence. Overlapping returns and rolling windows reduce effective independence.
- Retain failures. Missing windows and unstable estimates remain visible in the result table.
Prevent mechanical relationships
Control Rolls, Events, Revisions and Search Degrees of Freedom
A correlation can be manufactured by construction choices. Freeze the continuous-series rule, event taxonomy, sample exclusions and candidate list before opening the validation segment.
| Confound | Required control | Failure signal |
|---|---|---|
| Contract migration | Match dated expiries or use separately documented roll mappings | Relationship appears only at splice dates |
| Shared USD quote | Include an external broad-dollar control and non-USD comparison | Effect vanishes after the common factor |
| Scheduled releases | Tag official RBNZ, Stats NZ and U.S. publication timestamps | Estimate depends on a few event bars |
| Data revisions | Use vintage-aware macro data or enforce release-time availability | Revised values improve historical fit |
| Multiple comparisons | Register candidates and report family-aware uncertainty | Only the best of many undisclosed pairs survives |
CME DataMine distinguishes settlements and order-level products; the CFTC Commitments of Traders program publishes position categories and report documentation. Neither is a substitute for a timestamped, licensed research manifest.
Try to break the relationship
Predeclare What Would Make the Correlation Unusable
Robustness is not finding a window that restores the preferred sign. It is exposing the same registered claim to reasonable alternate histories and accepting rejection.
Temporal
Does the sign persist?
- Early versus late chronological blocks
- Adjacent non-overlapping horizons
- Daylight-saving and holiday variants
Structural
Does the channel persist?
- With broad-dollar and rate controls
- Event versus non-event periods
- Roll-proximate versus ordinary dates
Decision
Does it add value?
- Later sealed sample
- Risk-matched naive baseline
- Latency, spread, slippage and fees
Acceptance decision
Correlation Acceptance Record
Complete this record for each candidate. A blank required field or unstable estimate closes the claim; it does not become a qualitative signal.
Decision: accept, limit, or reject
- Definition
- Pair, returns, clock, rolls, window, estimator and sample hash.
- Evidence
- Estimate path, uncertainty, controls, all variants and sealed holdout.
- Use
- Declared decision, baseline, execution delay, costs and invalidation.
- Accept
- Direction and useful magnitude remain stable under registered checks.
- Limit
- Relationship is state-specific and the state is observable without hindsight.
- Reject
- Sign flips, interval is too wide, control removes it, or no net decision value appears.
No original 6N correlation study, coefficient, confidence interval, regime finding, predictive test or trading result is reported here. This page defines a protocol. Until a sealed study passes the record, the conclusion is not tested.
Sources, methods and editorial disclosure — reviewed August 20, 2026
- CME Rulebook Chapter 258: New Zealand Dollar/U.S. Dollar futures for dated-contract identity and exchange rules.
- CME New Zealand Dollar futures contract page for current product context; full mechanics are intentionally delegated to the canonical 6N specification guide.
- CME DataMine historical-data catalog for distinctions among settlements and order-level datasets. No CME market dataset was purchased or analyzed for this article.
- Reserve Bank of New Zealand B1 exchange rates and Trade Weighted Index for official daily reference-series definitions.
- CFTC Commitments of Traders reports and documentation for official positioning-data context.
- NIST/SEMATECH time-series analysis guidance for dependence and time-order context.
Sources and methods were reviewed August 20, 2026. This unsponsored article distinguishes contract facts, candidate mechanisms, testable hypotheses, statistical inferences and trading applications. It reports no original market result.